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Summary: In this Article, you will learn about the types of Inheritance in Java. Single-level inheritance Multi-level Inheritance Hierarchical Inheritance Multiple Inheritance Hybrid Inheritance Read more to know each in detail. Introduction Inheritance is a critical feature in which one object acquires the properties of the parent class. It is a crucial aspect of  OOPs (Object Oriented programming systems). Before understanding inheritance, let’s briefly understand Java. Inheritance in Java is the core feature of object-oriented programming. It facilitates a derived class to inherit the features from the parent class, through this hierarchical process the classes share various features, attributes, methods, etc. What is Java? Java is a general-purpose programming language that is class-based and object-oriented. Java helps the code developers to quickly write and run the code anywhere without worrying about the computer architecture. It is also known as “Write Once, Run Anywhere(WORA). Once compiled,  the code can run on all platforms without recompilation. The WORA attribute of Java is what makes the Java platform independent, as Java is one of the most highly demanded languages. Check Out upGrad’s Java Bootcamp Why Java? Easy to learn. Object-Oriented Programming Language (OOPs) Support Multithreading Multiple platforms friendly Secure  The programming language “Java” is widely used in the development of applications for mobile, web, desktop, etc. It is a robust, high-level, and object-oriented programming language developed by Sun Microsystems in 1995. Despite being a programming language, Java has an API and a runtime environment (JRE) and therefore, is also called a platform. Check Out upGrad’s Python Bootcamp Several concepts are there in Java, with four main concepts to get hold of the language. They are abstraction, encapsulation, inheritance, and polymorphism.  In this article, we will be focusing on the concept of inheritance in Java and the types of inheritance in java. Check out our free courses to get an edge over the competition. upGrad’s Exclusive Software and Tech Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4   What is Inheritance? As the name suggests, inheritance means inheriting properties.  The mechanism by which a class is allowed to derive the properties of a different class is termed inheritance.  With the concept of inheritance, the information in a program can be organized hierarchically. Inheritance is one of the critical features of OOPs (Object Oriented Programming System), where a new class is created from an existing class (parent or base class). In simple terms, the inheritance would mean passing down the characteristics of parents(habits, looks, height) to their child. The most useful contribution of types of inheritance in java would be the reusability of a code. As discussed earlier that the derived class would inherit the feature, methods, etc from the parent class so the codes present in the parent class would also be inherited into the derived class, this is how reusability would work. Different types of inheritance in java are also mentioned in the article. In Java, the concept of inheritance allows the users to create classes and use the properties of existing classes.  Learn Java Bootcamp from upGrad A few important terminologies associated with the concept are: Class: It is defined as a group of objects sharing common properties. Sub Class: Also known as a derived or extended class, this class inherits the features from another class. Also along with the inherited fields and methods, the class generated from the class can add fields and methods of its own. Super Class: The superclass represents the class whose features are inherited by a sub-class. Reusability: The technique of reusability allows the user to create a class (a new one) having the fields or methods of an already existing class. It allows reusing the code. Learn Software Courses online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career. Read: Learn java online for free! What are the 4 types of inheritance? In object-oriented programming, there are four main types of inheritance: single, multiple, multilevel, and hierarchical. Single inheritance allows a class to inherit features from one superclass, facilitating straightforward and clean inheritance structures. Multiple inheritance enables a class to derive attributes and behaviors from more than one superclass, offering versatility but also complexity. Multilevel inheritance involves a class inheriting from a derived class, creating a “grandparent-parent-child” relationship. Lastly, hierarchical inheritance permits multiple classes to inherit from a single superclass, useful for creating a family of related classes with shared characteristics. Types of Java Inheritance with Examples The different types of inheritance are observed in Java: Figure: 1 1. Single level inheritance in Java As the name suggests, this type of inheritance occurs for only a single class. Only one class is derived from the parent class. In this type of inheritance, the properties are derived from a single parent class and not more than that. As the properties are derived from only a single base class the reusability of a code is facilitated along with the addition of new features. The flow diagram of a single inheritance is shown below: Figure 2: Graphical illustration of single-level inheritance Source Two classes Class A and Class B are shown in Figure 2, where Class B inherits the properties of Class A. Example: An example of a code applying single-level inheritance Source Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript 2. Multi-level Inheritance in Java The multi-level inheritance includes the involvement of at least two or more than two classes. One class inherits the features from a parent class and the newly created sub-class becomes the base class for another new class. As the name suggests, in the multi-level inheritance the involvement of multiple base classes is there. In the multilevel inheritance in java,  the inherited features are also from the multiple base classes as the newly derived class from the parent class becomes the base class for another newly derived class. Figure 3: A flow diagram of multi-level inheritance Source From the flow diagram in Figure 3, we can observe that Class B is a derived class from Class A, and Class C is further derived from Class B. Therefore the concept of grandparent class comes into existence in multi-level inheritance.  However, the members of a grandparent’s class cannot be directly accessed in Java. Therefore, Figure 3 shows that Class C is inheriting the methods and properties of both Class A and Class B. An example of multi-level inheritance is shown below with three classes X, Y, and Z. The class Y is derived from class X which further creates class Z.  Example: An example of multi-level inheritance Source Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses 3. Hierarchical Inheritance in Java The type of inheritance where many subclasses inherit from one single class is known as Hierarchical Inheritance.  Hierarchical Inheritance a  combination of more than one type of inheritance. It is different from the multilevel inheritance, as the multiple classes are being derived from one superclass. These newly derived classes inherit the features, methods, etc, from this one superclass. This process facilitates the reusability of a code and dynamic polymorphism (method overriding). Figure 4: Graphical representation of a hierarchical inheritance. In Figure 4, we can observe that the three classes Class B, Class C, and Class D are inherited from the single Class A. All the child classes have the same parent class in hierarchical inheritance. Example: An example of code showing the concept of hierarchical inheritance Source The above code produces the output meowing… eating… Other than these types of inheritance in Java, there are other types known as multiple inheritances and hybrid inheritance. Both types are not supported through classes and can be achieved only through the use of interfaces.  In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses 4. Multiple Inheritance in Java Multiple inheritances is a type of inheritance where a subclass can inherit features from more than one parent class. Multiple inheritances should not be confused with multi-level inheritance, in multiple inheritances the newly derived class can have more than one superclass. And this newly derived class can inherit the features from these superclasses it has inherited from, so there are no restrictions.  In java, multiple inheritances can be achieved through interfaces. Figure 5: Representation of multiple inheritances Source Figure 4 shows that Class C is derived from the two classes Class A and Class B. In other words it can be described that subclass C inherits properties from both Class A and B. Learn Java Tutorials Java Tutorials Java Classes and Objects Java 8 features Operators in Java Static Keyword In Java Switch Case In Java Packages in Java For Loop in Java Thread Lifecycle In Java OOP vs Functional vs Procedural Instance variables in Java Loops in Java Identifiers in Java Java Frameworks String Comparison in Java charAt() in Java View All Java Tutorials 5. Hybrid Inheritance in Java Hybrid inheritance is a combination of more than two types of inheritances single and multiple. It can be achieved through interfaces only as multiple inheritance is not supported by Java. It is basically the combination of simple, multiple, hierarchical inheritances. Figure 6: Representation of a hybrid inheritance Source Figure 7 With the different types of inheritance in Java, the ultimate aim is to create sub-classes having properties inherited from the superclasses. The created sub-classes have various properties which are: Fields and methods inherited in a subclass can be directly used. New fields and methods can also be declared in the subclass which is not present in the superclass. A new instance method can be created in the subclass having the same signature as the method in the superclass. The process is referred to as overriding. A new static method can be created in the subclass having the same signature as the method in the superclass. The process is referred to as hiding. Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? Importance of Java inheritance Implementation of inheritance in Java provides the following benefits: Inheritance minimizes the complexity of a code by minimizing duplicate code. If the same code has to be used by another class, it can simply be inherited from that class to its sub-class. Hence, the code is better organized. The efficiency of execution of a code increases as the code is organized in a simpler form. The concept of polymorphism can be used along with inheritance.  Syntax The basic syntax is Class superclass { —————-  } class subclass extends superclass   {   ————– —————–  }   The keyword “extends” is used while inheriting a class. It defines that the functionality of the superclass is being extended to the subclass. The new class created is called a sub-class while the inherited class is termed a parent class. Two classes Calculation and My_Calculation are created in the above example. The methods addition() and Subtraction() are inherited from the class calculation into the My_Calculation. Keyword extends has been used for inheriting the methods. The compilation and execution of the above code give the following output. The creation of the My_Calculation class copies the contents of the superclass into the sub-class. With the objects of the subclass, the users can access the subclass member. In certain cases when we have to differentiate between the members of the sub-class to that of the superclass having the same names, the keyword “super” is used. If supposedly we have two classes Sub_class and Super_class having the same method i.e. display(). The implementation of the method is different but has the same name. In such a case, to differentiate between the method superclass from that of the sub-class, the super keyword has to be used. Conclusion Java is a significant programming language, which makes it suitable for other programming tasks. It is easy to write, and compile than other programming languages. It has multiple applications such as finance, e-commerce, and applications development. Ranked as third-most sought-after programming language for hiring managers globally (PDF, 2.4 MB). It has held #5 spot on Stack Overflow’s list of the most commonly used languages for two years.  Its versatility has contributed to its appeal and demand. Its versatility has contributed to its appeal and demand. The article discussed the important concept of inheritance in Java and the types of inheritance in Java. Inheritance is therefore the mechanism where we can reuse the codes in order to acquire the properties of a class into another class. This can be achieved through the different types of inheritance patterns as shown in the article. However, there is much more to the concept of inheritance. To excel in the field of development, mastering in the complex programming of Java is required. If you have a dream of innovating intelligent devices, then Executive PG Program in Full-stack Software Development offered by upGrad’s would be the best choice. Certified from the Liverpool John Moores University, the course in association with IIIT Bangalore offers 500+ learning hours and is designed for early professionals. The skill learned from the upGrad’s course will help in opening up opportunities towards the field of software development, web development, javascript developer, etc. Open to any gender within the age group of 21-45, the interactive program might be the best choice for all the coders.

by Arjun Mathur

20 May 2024

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165964

Attending an agile interview and wondering what are all the questions and discussions you will go through? Before attending an agile testing interview, it’s better to have an idea of the type of agile interview questions so that you can mentally prepare answers for them. Let’s accept, we all get a bit nervous about interviews. No matter how capable you are or how much experience and knowledge you possess, at the end of the day, interviews are about how do you present yourself, how well you manage to put your knowledge into answering the questions in the most suitable way. Hence, it is always preferable to do a bit of research before an interview. Revise answers, brush up our skills. ‘doing’ and ‘explaining how to do’ are two different things. Agile interview questions and answers can include all aspects of the Agile methodology. The list below will help you become a pro! Agile methodology is an iterative project management technique that prioritizes cross-functional collaboration and continuous improvement. It segregates the project into different phases and directs the team through planning, evaluation, and execution. Scrum and Agile team members play an integral role in any organization.  Whether you are an expert or a novice in the world of Agile technology, these Agile interview questions can help you immensely in your technical rounds. We have briefly brushed upon all levels of difficulty in this article on Agile methodology interview questions for freshers & experienced. Check out our free courses related to software development. One-Of-Its-Kind Program That Creates Skilled Software Developers. Apply Now! Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript Recently, the Agile Methodology has gained traction in the industry, with an increasing number of companies incorporating the concept into their organizational infrastructure. As a result, job postings in this domain is increasing rapidly. If you, too, wish to land a promising job in the IT sector, you must be well-versed in the Agile Methodology. Check out our Advanced Certification in Blockchain In this article, we will be looking at some most important agile interview questions and answers. There are certain agile methodology questions that are generally asked in an interview. We’ve created this agile interview questions and answers guide to understand the depth and real-intend behind the questions. These Agile questions and answers will address all your queries about the subject and give you a better understanding of the methodology.  Top Agile Interview Questions & Answers 1. What is Agile Testing? The first question of agile interview question tests your knowledge about the basic of agile testing. Agile testing is a practice based on the principles of agile software development. It includes all members of an agile team with specific skills and a certain expertise to ensure the timely delivery of a product with the release of additional features at frequent intervals. Check out our Advanced Certification in Cloud Computing 2. How is Agile Methodology different than Traditional Waterfall process? Characteristic Agile Methodology Traditional Waterfall Process Development Approach Iterative and incremental, allows for flexibility and adaptation Sequential and linear, follows a fixed plan Requirements Flexible, can change throughout the project Fixed at the beginning, difficult to change mid-project Delivery Schedule Regular and frequent releases, prioritizing working software Single delivery at the end of the project Feedback Constant feedback and collaboration with stakeholders Limited feedback until project completion Risk Management Risks are identified and addressed continuously Risk assessment occurs at the beginning of the project Quality Assurance Testing is integrated throughout the development process Testing occurs after development is complete Customer Involvement Customers are involved throughout the development process Customer involvement is limited to the requirements phase Documentation Minimal documentation, emphasis on working software Comprehensive documentation at each phase of development Project Control Adaptive and responsive to change, with regular reviews Less adaptable to change, requires strict adherence to plan Team Structure Cross-functional teams collaborate closely on tasks Distinct roles and responsibilities for different teams This is the most commonly asked agile interview question. In agile methodology, features of the software are delivered frequently, so that the testing activity is done simultaneously with the development activity. Testing time is shortened as only small features are need be tasted at once. Source While, in the waterfall model, testing activities take place at the end of the entire development process. Testing time, in this case, is as long as the entire product is to be tested in one go. Waterfall methodology is a closed process where all stakeholders are not involved in the development process whereas agile methodology requires the involvement of various stakeholders including customers. Learn more about agile vs waterfall. A Beginner’s Guide to MVC Architecture in Java 3. What are the pros and cons of Agile Methodology? This is one of the most frequently asked agile interview questions. Pros of the agile methodology: Speedy and continuous delivery of the software ensures customer satisfaction. All the stakeholders (customers, developers, and testers) are involved in the process which leads to technical excellence and good design. It facilitates close interaction between business people and developers. Its flexibility ensures the adaptation to changing circumstances. Changes added at the last moment or at a later stage of development can be incorporated without any problem. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses upGrad’s Exclusive Software and Tech Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4   However, it does have some disadvantages too: Sometimes when software deliverables are large ones, it is tough to determine the effort level required at the beginning of the software development lifecycle. In agile methodology, documentation and designing take a back seat. The decision-making crucial for the development process comes with seniority and experience. Hence, freshers can hardly manage to find a place in the agile software development process. Get Software Engineering degrees from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career. 4. What kind of projects is suitable for the Agile Methodology? The traditional methodology is suited for projects with predefined, clearly stated requirements while agile development methodology is suitable for projects with dynamic requirements where frequent changes in the product come up on a regular basis. 15 Must-Know Spring MVC Interview Questions 5. What are the different types of Agile Methodologies? An agile interview question and answers guide will not be complete without this question. There are several types of agile development methodology. Scrum is one of the most popular and widely used agile methods. Other types of agile development methodology are; development like Crystal Methodology, DSDM(Dynamic Software Development Method), Feature-driven development(FDD), Lean software development and Extreme Programming(XP). Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses 6. Difference between extreme programming and scrum? Characteristic Extreme Programming (XP) Scrum Primary Focus Software engineering practices and coding Project management and collaboration Iterations Continuous, short iterations with frequent releases Fixed-length iterations (sprints) with regular reviews Roles No fixed roles, emphasis on teamwork and collaboration Defined roles: Product Owner, Scrum Master, Team Requirements Flexible and adaptable, can change frequently Fixed for the duration of the sprint Feedback Constant feedback from customers and team members Regular feedback during sprint reviews and retrospectives Documentation Emphasis on working software over comprehensive documents Minimal documentation, focus on communication Testing Test-driven development (TDD) is a core practice Testing integrated throughout the development process Meetings Regular meetings include daily stand-ups and planning Structured meetings: sprint planning, review, retro Scaling Suitable for small to medium-sized teams and projects Scalable for larger teams and complex projects Culture Emphasizes technical excellence, teamwork, and simplicity Emphasizes transparency, collaboration, and adaptation Scrum teams usually have to work in iterations which are known as sprints which generally last up to two weeks to one month long while XP team works in the iteration that lasts for one or two weeks. XP teams are more flexible as they can change their iterations while Scrum teams do not allow any change in their iterations. The product owner prioritizes the product backlog but the team decides the sequence in which they will develop the backlog items in scrum methodology. Whereas XP team works in strict priority order, features developed are prioritized by the customers. Our learners also read: Java free online courses! 7. Can you explain the lean methodology in detail? Lean software development method follows the principle of “Just in time production”. It aims at increasing the speed of software development and decreasing cost. The basic idea of lean is to reduce non-value-added activities (known as “wastes”) in order to increase customer value. The agile process itself is a lean method for software development lifecycle. However, activities like backlog grooming (when team review items on the backlog to ensure the appropriate items are in the backlog, that they are prioritized well, and that the items at the top of the backlog are ready for delivery) code refactoring (process of restructuring existing computer code – changing the factoring — without changing its external behavior) fits agile methodology more in tune with lean principles. What is Test-driven Development: A Newbie’s Guide 8. What is Kanban? It is one of the common agile interview questions. Kanban is a tool which helps the team to keep a close eye the work i.e., to measure its progress. Apart from the progress, the status of a development story can be seamlessly described with the help of ‘kanban board’. Kanban board aids in writing the whole scenario of a project at a single place to give a perfect picture of the bottleneck, a task done, workflow progress. It helps in the continuous delivery of the product without overburdening the team. 9. Is there any difference between incremental and iterative development? Characteristic Incremental Development Iterative Development Definition Builds and delivers the project in small, usable increments Builds and enhances the project through repeated cycles Focus Each increment adds new features or functionality Each iteration refines and improves existing features Delivery Partial solutions are delivered incrementally Full solutions are delivered in each iteration Feedback Feedback is gathered after each increment Feedback is gathered and applied in each iteration Risk Management Risks are addressed incrementally as new features are added Risks are managed through continuous refinement Flexibility Provides flexibility to adapt to changing requirements Allows for flexibility and refinement throughout the process Timeline Each increment has its own timeline and delivery schedule Iterations have fixed time frames, typically 1-4 weeks Customer Involvement Customers can provide feedback early and often Customer feedback shapes each iteration of development Testing Testing occurs incrementally as features are added Testing is integrated into each iteration of development Scope Scope may evolve with each increment Scope remains constant within each iteration Yes, the iterative methodology is a process of software development without any interruption. In this method, software development cycles consisting of sprint and release are repeated until the final product is obtained. Whereas, the incremental model is a process of software development where the product is designed, implemented and tested incrementally until the product is finished. It involves both development and maintenance. 10. What are burndown and burn-up charts in agile methodology? To track the progress of an ongoing project, these charts are used. Burn-up charts indicate the work that has been completed while Burn-down chart shows the amount of remaining work in a project. Why Companies are Looking to Hire Full Stack Developers 11. Can you explain pair programming and its benefits? It is one of the general agile interview questions and answers guide. The combined effort in the team where one programmer writes the code and the other one reviews it is called pair programming. There are several benefits of pair programming, it not only improves the quality of code but also facilitates the knowledge transfer. It reduces the chance of mistakes as two people are simultaneously working on a code. 12. Do you know what is the scrum of scrums? This is one of the most important Agile interview questions. The term “Scrum of Scrums” is used when there are multiple teams involved in a project. It refers to the scaling of the daily Scrum meeting. In this scenario, each team is responsible for conducting and leading its separate scrum meeting. However, to maintain coordination and communication among all the different teams, a separate meeting must be conducted wherein all the teams participate. This is known as the “Scrum of Scrums.” In this meeting, one team leader from every team (known as the “ambassador”), will represent their team. The main idea behind this is to encourage Agile teams to collaborate and coordinate their work with each other.  13. What is the velocity of a sprint and how it is measured? This question is categorized under agile project management interview questions and is among the most frequently asked ones.  Velocity is one of the planning tool used to estimate the speed of the work and time of completion of the project. The calculation of velocity is done by reviewing the work team has successfully completed during earlier sprints; for example, if the team completed 5 stories during a two-week sprint and each story was worth 3 story points, then the team’s velocity is 15 story points per sprint. How to Become a Full Stack Developer 14. According to you what are some qualities that a good agile tester must have? A competent agile tester must possess the following qualities: They should be capable of understanding the requirements quickly. An agile tester should be aware of all the agile principles and concepts and values as listed down in an agile manifesto. They should be able to prioritize the work based on the requirements. They should have excellent communication skills as continuous communication between business associates, developers and tester is a backbone of the agile development process. 15. Can you list some responsibilities that a scrum team have to undertake? This is one of the important agile interview questions. Major responsibilities that a scrum team has to include: Breaking down the requirements, creating tasks, estimating and distributing the created tasks. To put simply they are in charge of creating sprint backlogs. They have to arrange daily sprint meeting. It is a responsibility of the team to ensure that every functional feature is delivered on time. They have to create a sprint burndown diagram to know to get the exact estimate of work done and the work that needs to be done. 16. Mention the principles of Agile testing. Not many people are aware of the importance of such Agile questions. The principles of Agile testing are: Continuous testing – This ensures the continuous progress of the product. An interesting aspect of the Agile testing process is that unlike the traditional methodologies where only the testing team is focused on product testing, it requires the entire team to participate equally in the testing process.  Continuous feedback – With every test, the client feedback is encouraged to ensure that the product meets the business requirements of the client.  Simple and clean code – Whatever errors and defects arise during the testing phase are fixed within the same iteration by the Agile team. This allows for simple, concise, and clean code.  Less documentation – Agile teams use a reusable checklist. Here, they are more focused on the testing process rather than the incidental details. 17. Differentiate between Agile and Scrum. A critical agile interview question you need to be aware of. Agile and Scrum have their fair share of similarities and differences. Since Scrum is a part of the Agile Methodology, both of them promote the completion of projects incrementally in small fragments. Also, both methodologies are iterative in nature. However, the main difference between Agile and Scrum is that the former has a broader spectrum. While Agile Methodology is used for project management, Scrum is ideal for projects where the requirements change rapidly. In the Agile Methodology, leadership holds the most pivotal position, whereas Scrum encourages the creation of a self-organizing and cross-functional team. 18. What are the crucial Agile Matrices?  Some of the essential Agile Matrices are: Velocity – It is essential to keep track of the project’s velocity so that the Agile team can have a clear about your progress, capacity, and other metrics.  Work category allocation – Allocating separate work categories provides a clear idea about where different team members are investing their time and what is the order of priority of the various tasks in a project.  Defect removal awareness – When team members work proactively and correct the errors simultaneously as they develop and test a product, the quality of the end product improves significantly. Cumulative flow diagram – It represents a workflow in which the x-axis represents time, and the y-axis depicts the effort of members.  Sprint burn-down matric – This allows the Agile team to track and monitor the completion of the work along with the sprint. Deliver business value – It is primarily concerned with the overall work efficiency of the Agile team. Only when all the team members are productive that the Agile team can deliver business value to their clients.  Time coverage – The time required to develop and test each iteration is measured using the ratio between the number of lines in a code (test suite) and the number of relative lines of codes. Defect resolution time – As the name suggests, it pertains to the time required to detect and fix bugs and issues. This is an elaborate process that requires the Agile team to collaborate and deliver improved results in the most productive manner possible. 19. Explain “Zero Sprint” in Agile. One of the important agile interview questions. In Agile Methodology, Zero Sprint refers to the first step that comes before the first sprint. So, it is more like a pre-step to the first sprint. Thus, Zero Sprint would include a host of activities that are to be completed before starting a project, including setting up the development environment, preparing backlog, and other such tasks that are usually done before beginning the actual development process.  20. What is the ideal duration of a Scrum Sprint? The duration of a Scrum Sprint or the Scrum Cycle primarily depends on the project size and the team working on it. A Scrum team may consist of 3-9 members, and it takes about 3-4 weeks to draft and complete a Scrum script. Going by this calculation, the average duration of a Scrum Sprint is four weeks. 21. Explain the role of the Scrum Master. One of the popular agile interview questions. The Scrum Master is the leader and supervisor of the Scrum team. The main job of the Scrum Master is to ensure that the team abides by the Agile values and principles and follows the agreed-upon processes and practices. Some of the most crucial responsibilities of the Scrum Master are: To eliminate all the obstacles that could hamper the productivity of the Scrum team. To establish a productive and collaborative work environment for the Scrum team. To protect the team from the interruptions and distractions of the outside world. To maintain a good relationship between the team, clients, and all the other stakeholders involved in a project.  To supervise the operations of the Scrum team and motivating them as and when needed.  22. Differentiate between “Sprint Planning Meeting” and “Sprint Retrospective Meeting.” Although the two terms may sound similar, Sprint Planning Meeting and Sprint Retrospective Meeting are quite different from one another. A Sprint Planning Meeting involves all the Scrum roles – product owner, scrum team, and scrum master – coming together to discuss the project priorities and backlog items. Usually, the Sprint Planning Meeting is a weekly event that lasts for about an hour. A Sprint Retrospective Meeting, on the other hand, is one where all the Scrum roles (product owner, scrum team, and scrum master) come together to discuss the good and bad elements of the sprint and the sprint improvements. This meeting is generally an extension of the Sprint Planning Meeting and can last up to two to three hours. Apart from these agile methodology interview questions, questions based on your previous experience in case you are already acquainted with agile methodology can be asked by the interviewer. You might want to revisit your on-the-job learnings and prepare answers to questions like: How long were your sprints for the projects you have worked on? What is the maximum number of scrum you have handled at a time? What kind of project management tools were used for your project? Have you used automated test tools earlier? How was your experience? Did your iterations overlap? 23. Is agile development a framework? Agile signifies all-embracing values for software development. It emphasizes the value of iterating rapidly and frequently to meet customers’ expectations. So, an agile framework is defined as an explicit software-development approach depending on the Agile philosophy expressed in the Agile Manifesto. 24.What are Agile Methodology Frameworks? It is one of the common Agile capital services interview questions. The Agile framework works on the Agile approach that offers data on the particular Agile-development practices. The disparities in the software development processes lead to Agile frameworks. The Agile methodology frameworks are also known as processes or methodologies. They lay the basis of Agile transformation. Some of the prominent Agile methodology frameworks used are  Scrum, Disciplined Agile, The crystal method, Scaled Agile Framework (SAFe), Feature Driven Development (FDD), Lean Software Development (LSD), Rapid Application Development (RAD), Scrumban, and Kanban. 25.How to enhance the impact of Agile? You can include this question when preparing for the Agile capital services interview questions. Considering the increasing adaptation of Agile in many organizations, Agile’s impact renders the desired outcomes of effective agile transformation. The four metrics included in the Agile impact framework are customer satisfaction, operational performance, employee engagement, and financial performance. Organizations can assess the Agile impact by determining how Agile teams enhance the customer experience. Alternatively, you can do that by comparing the new values generated by Agile teams with the traditional waterfall output’s value. 26.How do you deal with distributed teams in Agile? Dealing with distributed teams is significant in many organizations. So, this one is one of the frequently asked Agile interview questions. The following tips help you to deal with distributed teams in Agile. (i) Uniformly distribute work and maintain apparent task allocation. (ii) Recruit self-reliant and dedicated individuals to fulfil the vision.  (iii) Create co-located teams and let them invent ways to share the work. (iv) Capitalize on collaboration technology to increase teamwork efficiency. (v) Arrange daily stand-up meetings to explore potential roadblocks and decrease dependencies. Read: Must Read Top 58 Coding Interview Questions & Answers 27.How are Agile and DevOps different? Many leading organizations ask these types of Agile interview questions. Agile and DevOps both started their journeys to enhance the software development process. Agile prioritized working on software development rather than rigid processes. DevOps prioritized production and development. They both share a fundamental concept, but they target diverse stakeholders with unique business objectives. Each of them addresses dissimilar yet critical parts of software development. Agle sets the stage for DevOps and provides ways to develop software faster. On the other hand, DevOps focuses on quality and offers teams to deploy frequently. 28.How does Agile save you money? It is one of the popular Agile interview questions and answers from a business perspective. Agile processes are cost-effective. They are well-known for quality assurance, scope optimization, and cost saving. It only focuses on developing only the required aspects to save time and let businesses generate more revenue. The quality of deliverables is guaranteed when the iteration terminates. Agile reduces the completion time by motivating the compartmentalization of work. Agile delivery is faster because it focuses on high-priority tasks. Communication transparency guarantees faster product delivery. So, time saved ultimately saves money. 29.When should you use Agile project management? Companies have adopted an agile style of project management that stresses fostering collaboration and efficiency. This particular question is categorized as one of the popular agile project management questions and answers from a managerial perspective.  It is one of the common Agile interview questions and answers when it comes to enhancing organizational work efficiency. Agile characteristics like iteration, adaptability, short time frames, and continuous delivery make it suitable for project management. So, Agile is suitable for continuing projects and projects where some details are unknown at the outset. Agile project management is therefore useful when a project lacks clear timelines or resources. For example, designing a new product may create some challenges. Implementing an Agile methodology allows frequent product testing, quick iteration, and smooth communication with stakeholders. 30.Which is the best Agile method? This is one of the common agile questions when studying different Agile methods. Scrum is the best and most extensively used Agile methodology globally. The Scrum framework addresses two critical pain points of software development i.e. speed and altering client requirements. This approach executes the software development project in phases and each phase is called a Sprint. 31.How agile methodology is more advantageous compared to traditional methodologies? The key difference between Agile and traditional approaches is the order of project phases – gathering requirements, planning, designing, development, testing, and UAT. The sequence of the project development phase is linear in traditional development methodologies, whereas it is iterative in Agile. Testing is undertaken after the development phase completes in Agile methodology. Testing and development occur simultaneously in traditional methodologies. Client involvement is less in traditional development than in Agile development. Traditional methodologies are less secure. 32. How agile methodology works in testing? It is one of the advanced level Agile questions. Testing happens early and frequently in Agile development. Rather than waiting for development to be completed before testing starts, testing takes place constantly as features are added. The tests are prioritized similarly to user stories. Testers target to complete as many tests as possible. 33.What is included in the Agile Testing Lifecycle in Scrum? The Scrum Agile testing lifecycle includes the following points. (i) Contributing to user stories according to the system’s expected behaviour  (ii)Release planning as per test defects and effort. (iii)Sprint Planning according to user defects and stories. (iv)Sprint execution with continuous testing. (v)Regression testing after the Sprint planning completes. (vi)Reporting Test Results. (vii)Automation Testing 34.When to choose Agile methodology? It can be considered as expert-level Agile questions and answers. Agile methodology can be chosen in the following scenarios. (i) The developers are ready to lose work of a few days or hours when implementing a new feature. (ii) When limited planning is needed to begin the project. (iii) When there is more focus on what has to be done and less focus on scheduling and documentation. (iv) When requirements and priorities need to be easily adjusted all through the project to fulfil the stakeholders’ needs. 35.What are the risks of using agile methodology? Certain organizations may ask these types of Agile questions and answers in interviews. Here are the three key risks of using Agile methodology. (u) Budget risks –It denotes that occasionally, it’s difficult to accurately estimate the cost of a new product’s development during its early stages. (ii) Scope creep risk –It assumes scope changes during the development that leads to changing deliverables, shifting timelines, and budget increases. (iii) Less predictability -Agile adopts constant changes and it is occasionally challenging to provide long-term predictions. This risk deals with changing the deadlines for the vendor. 36. What is the Agile Manifesto and its core values? This is one of the agile interview questions that do not come under the technical repository of questions, but you must be familiar with the topic. The Agile Manifesto is a documentation that outlines four fundamental values and twelve principles that software developers should implement to guide their work. The developers who introduced the Agile Manifesto sought to find stability between existing ways of development and other possible alternatives.  The four core values documented in the Agile Manifesto are as follows: Individuals and interactions should be given priority over processes and tools. Demonstration of working software at regular time intervals over comprehensive documentation. Precedence to be given to customer collaboration over contract negotiation. Incorporating change over following a project plan.  37. What do you mean by Scrumban? This is one of the latest interview questions on agile methodology, as Scrumban is one of the core developments in agile procedure. Scrumban is a project management strategy that combines two Agile methods — Scrum and Kanban. It integrates Scrum’s structured framework of sprints, standups, and retrospectives with Kanban’s visual workflow. This allows teams to benefit from iterative development and continuous flow, enhancing adaptability and efficiency. Scrumban came into prominence to help software teams switch from Scrum to Kanban and vice versa. If the teams are competent in working with both methodologies, this layout can assist them in the smooth shift to other methodologies. 38. What are Scrum Ceremonies, and name the essential team members in them? Scrum Ceremonies, also termed events, are gatherings that occur before, during, and subsequent sprints embedded in the scrum framework. The framework partitions projects into regular intervals, for example, 30 days to complete the task. During a scrum sprint, they allow ease in communication.  The prominent team members include: Scrum Master – The Scrum Master ensures that everyone in the team has the equipment and guidance to be productive. The Scrum Master schedules meetings and conveys the team’s progress and problems.  Product Owner – The product owner takes essential decisions and prioritizes each item before a Scrum sprint. They constitute the interests of the clients and stakeholders. Development Team – The development team is a cross-functional group that develops the product. This group comprises developers, quality assurance analysts, and designers involved in transporting and developing products. 39. What are the quality strategies of agile? This is one of the basic agile methodology interview questions.  Initiation – During formation, it is often termed Sprint 0 in Scrum or Iteration 0 in agile technologies. The primary goal of the team leader is to define goals and guide the team in the right direction. From the point of view of testing, the main tasks have to be organized according to your approach to testing and commence setting up the test environment.  Development team strategies – Agile development teams adhere to a team strategy in which testers are inducted into the development team, and the team is held responsible for testing. This works in favor of many instances, but when your environment is composite, you will need an independent testing team to work in tandem with the development team.  Parallel independent testing – The team’s approach of inducting agile testers to the group is a significant start but doesn’t suffice in the long run. The idea is to constitute an independent test team that performs some advanced tests. This team does not require a detailed set of requirements but may require specifics such as architecture diagrams.  40. What do you understand by the term Daily Stand-Up? This is one of the frequently asked agile scrum interview questions. The Daily Stand-Up, or Daily Scrum, is a short, daily meeting in Scrum where team members discuss progress, plan for the day, and identify any obstacles. Participants stand to keep it brief, typically lasting 15 minutes or less, promoting quick updates and issue resolution. It is advisable to host these meetings in the presence of the project manager and with all employees in attendance.  41. What do you mean by impediments? State instances of impediments. Impediments are roadblocks or obstacles faced by the members of the Scrum team that affects the speed of their work. Impediments can assume various forms like – i) Missing resources or absence of a team member, ii) Business troubles, iii) Lack of essential skills or knowledge iv) organizational problems.  Certain organizations ask these agile testing interview questions to evaluate a candidate for a role where user stories will be used. These agile process interview questions test the candidate’s knowledge in understanding the customer’s perspective. If you are applying for a senior role, you must prepare these Agile methodology interview questions for experienced Agile testers. 42. What is a user story? A user story is a simple description of a feature delivered to the end users. User stories are used in agile technologies to understand the requirements of the customers or users. The purpose of a user story is to express how the company will add value to the customer’s requirements.  Also, Read Agile methodology Interview Questions for testers 43. What are the 3 Cs of user stories?  This is one of the scenario-based agile questions, The 3 Cs of user stories are: Cards – User stories are written on cards. They form the foundation for a conversation. It doesn’t matter what kind of card (digital, index, or post-in) is used. The written content on the card signifies the story’s priority and the cost involved. Conversation – A card portrays user requirements, but they have to be refined and presented to the developers. When a user story is documented on a card and written on a board, it reflects how committed the team is to discussing a user story. Confirmation – Confirmation is one of the criteria for acceptance prior to development. The team may preside over a meeting regarding a user story, but there lies an iota of suspicion if the user requirements are met or not. So, confirmation ensures that the user requirements have been delivered. Every individual who is a part of the scrum and agile team should uphold the company’s ethics and values. To explore the core components of Agile, have a look at this agile question and answer. 44. What do you mean by a Build-Breaker? A build-breaker is a team member responsible for impeding the team’s progress. The individual introduces probable changes to the applications that make them impossible to run.  The Steps of Agile Methodology Agile methodology aims to deliver more regular product launches and shorter project cycles than traditional project management. The Agile interview questions and answers mentioned above will help you understand the methodology in detail. Candidates can also create Agile interview questions and answers pdf for better access to questions for revision.  You may employ a variety of Agile models, including Kanban and Scrum, which are two among the most popular. However, any Agile approach will adhere to the same fundamental steps, which are as follows: 1. Planning the project  As with any other project, you should have a clear understanding of the final product, its value to the customer or company, and the way it will be accomplished before work starts. You may create a project goal here, but keep in mind that Agile project management’s goal is to make it simple to address modifications and modifications to the program. As a result, the scope of the project shouldn’t be viewed as impervious to change. 2. Developing a product roadmap An outline of the characteristics that make up the finished product is called a master plan. Due to the fact that you will develop each of these distinct features during each sprint, this is an essential part of the Agile planning phase. You will also create a product inventory at this time, which is a checklist of all the features that will go into the finished item. Later, while planning sessions, you can select items from this checklist. 3. Planning the release In traditional project management, there is one date that matters the most. The final date after all the planning and development is when you release the product. Agile, on the other hand, employs reduced development periods, also known as ‘sprints’, with features being delivered at the conclusion of each cycle. You will develop a comprehensive strategy for product releases before the project begins, and at the start of each sprint, you will review and reevaluate the plan. 4. Planning sprint The parties must have a sprint strategy meeting before the start of each sprint to decide what the role of each individual be and how it will be accomplished. To ensure that everyone on the team completes their allocated responsibilities throughout the sprint, it’s critical to distribute the workload fairly. A visual record of your workflow is also necessary for team transparency, shared knowledge, and the detection and elimination of bottlenecks. 5. Planning daily tasks Hold quick daily meetings to assist your team to complete their responsibilities throughout each sprint and determine if any adjustments are necessary. Each colleague will briefly discuss their upcoming daily tasks. These daily sessions should be brief.  How to Become a Full Stack Developer 6. Testing The testing stage checks whether the product meets the company guidelines and customer requirements. Testing is an indispensable part of the Agile life cycle and is performed while developing the product roadmap. As the developer teams continue to complete the unfinished tasks, the testing team will take over and continue executing test cases to identify bugs in the code. 7. Maintenance The maintenance stage establishes that the software meets user requirements over time. Your team needs to observe the software and resolve errors as and when they arise. You can collect feedback from users from different sources. The input gathered from the sources should be used to identify potential threats and arrive at a conclusive solution. To prepare for an upcoming interview where Agile questions and answers may be asked, it is necessary to understand all aspects of Agile methodology and go through the Agile interview questions and answers pdf thoroughly. Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? Tips to Help You Prepare For An Agile Interview as a Developer A simple way to prepare for agile methodologies interview questions is to use the repository of resources available in the public domain. Agile practices are used widely across a range of sectors from software development to healthcare and financial services. Digital.ai’s 16 State of Agile Report states the technology sector uses agile methodologies the most, almost 27%. It is crucial to understand global agile fundamentals to have clarity on the global impact of agile technology. This article covers all aspects of agile methodology interview questions and answers. Fundamental agile questions and answers are asked of candidates applying for entry positions and the level increases according to the role. Preparing for an Agile interview as a developer requires a combination of technical knowledge, practical experience, an understanding of Agile principles and methodologies, and many more things. So, keeping this in mind let’s learn some valuable tips to help you succeed in your Agile interview: Understand Agile Principles Before your interview, ensure you have a solid understanding of Agile principles and methodologies. Familiarize yourself with iterative development, collaboration, continuous feedback, and change adaptation. Know Scrum and Kanban Be well-versed in popular Agile frameworks like Scrum and Kanban. Understand the roles (Scrum Master, Product Owner, Development Team) and ceremonies (Sprint Planning, Daily Standup, Sprint Review, Sprint Retrospective) in Scrum, as well as Kanban principles such as visualizing work, limiting work in progress, and managing flow. Technical Skills Brush up on your technical skills, especially those related to the job you’re applying for. Be prepared to discuss programming languages, frameworks, version control systems, and other tools commonly used in Agile development environments. Practice Agile Tools Familiarize yourself with popular Agile tools like Jira, Trello, or Asana. Many Agile teams use these project management tools, so that hands-on experience can be a significant advantage. Collaboration and Communication Agile emphasizes collaboration and communication. Be prepared to discuss your experiences working in teams, how you handle conflicts, and how you communicate progress and challenges. Problem-Solving Scenarios Expect scenario-based questions where you might be asked how you would handle specific Agile-related challenges. Practice answering questions related to prioritizing tasks, handling scope changes, or resolving conflicts within a team. Continuous Improvement Agile focuses on continuous improvement. Be ready to discuss how you’ve contributed to process improvement in your previous projects. Discuss any initiatives you’ve taken to optimize workflows, increase efficiency, or enhance team collaboration. Cultural Fit Agile teams often have a unique collaboration, trust, and adaptability culture. Be prepared to demonstrate how your values align with Agile principles. Share examples of how you’ve worked in environments that value these principles. Be Adaptable Agile is all about adaptability. Show your willingness to learn and grow, emphasizing that you can easily adapt to new tools, methodologies, and project requirements. Ask Questions Finally, be prepared with thoughtful questions for the interviewer. Ask about their Agile processes, team structures, and how they handle challenges. This shows your interest and helps you assess if the company’s Agile practices align with your expectations. Conclusion With that, we come to the end of our list of agile interview questions and answers guide. Although these agile interview questions are selected from a vast pool of probable questions, these are the ones you are most likely to face. These were the must-know questions and answers revolving around the agile methodology. Most companies practice agile development in one form or another, thanks to the features it has to offer. If you wish to make a flourishing software development career, what are waiting for? Master agile methodology. Explore more about Agile software development, check out upGrad’s Executive PG Programme in Software Development – Specialisation in Full Stack Development.

by Arjun Mathur

18 May 2024

Blogs

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In this article, you will learn the 21 Interesting Web Development Ideas & Topics 2024. Take a glimpse below. Best Web Development Project & Topics For Final Year Students & Beginners One-page layout  Login authentication   Product landing page  Giphy with a unique API JavaScript quiz game To-do list SEO-friendly website JavaScript drawing Search engine result page Google home page lookalike Tribute page Survey form Exit the plugin Note log Social share buttons Toast notifications AJAX-style login Word Counter Countdown timer Modal pop-ups Address book Read the full article to know more about all the 21 Web Development project Ideas & Topics in detail. What is Web Development? Web development refers to creating websites and web applications for the Internet. It combines various skills, technologies, and disciplines to design, build, and maintain functional and visually appealing websites. Web development projects encompass everything from simple static web pages to complex dynamic web applications with interactive features. Key components of web development include: – Front-end Development This involves creating a website’s user interface and user experience. Front-end developers work with technologies like HTML (Hypertext Markup Language), CSS (Cascading Style Sheets), and JavaScript to design and implement the visual elements and interactivity users interact with. Back-end Development Back-end development involves building the server-side logic and databases that power a website or web application. Back-end developers use programming languages such as Python, Ruby, PHP, Java, or Node.js to handle data processing, authentication, server configuration, and other server-side tasks. Apart from working with server-side languages and databases, it also uses frameworks, APIs, and security measures to create the functional components of a website or application. It focuses on server management, security, and the core functionalities that power the user-facing elements developed in the front end. Full-Stack Development Full-stack developers have expertise in both back-end and front-end development. They can work on both the client-facing aspects and the server-side components of a web application. A full-stack developer possesses the skills and knowledge to handle various aspects of web development, from designing and building the user interface to managing databases and server-side logic. They are proficient in front-end technologies like HTML, CSS, and JavaScript. They can create responsive, visually appealing user interfaces and ensure a seamless user experience.  Web Development Project Ideas For College Students With digital presence becoming a necessity for brands to expand and gain exposure among potential customers, the web development industry is taking off rapidly, and so is the demand for Web Developers. In fact, web development has emerged as a promising field right now, attracting aspirants from all educational and professional backgrounds. As industries continue facing fierce competition among fellow brands and services, the ones keeping up with trends steal the limelight. The severe expansion of digitally engaged audiences has proved that web development is no more a choice but a necessity to reach a broader customer base, increase engagement and promote services.  You can also check out our free courses offered by upGrad under IT technology. Considering how web development is experiencing continuous growth with technological advancement, following web development trends is essential to sustain the audience’s volatile attention. Aspects like architecture, application, chatbots, motion UI, and IoT are popularly incorporated into service structures with API project ideas for beginners, demanding significant experience to master and create complying websites and applications.  Practicing web technology projects with code bridges the gap between theoretical knowledge and practical application, and the best way to grasp web development concepts is by working on real-world projects. Web development projects for final-year students or fresh graduates and API project ideas for beginners help them test their theoretical knowledge and enhance their practical skills.  If you are also interested in web development, working on web technology projects is the best way to upskill in this field. The more you practice and experiment with challenging web development projects, the better your real-world development skills will be. Enroll on the Job Guaranteed Full Stack Development Bootcamp program from upGrad. We’ve created this post to help you get an idea of the kinds of web development projects that you can work on. So, without further ado, let’s get started and get your hands on our web project ideas.  Top Web Development Projects Ideas This list of web development project ideas is suited for beginners & intermediate level learners. These web project ideas will get you going with all the practicalities you need to succeed in your career as a web developer. Further, if you’re looking for web development projects for final-year students, this list should get you going. So, without further ado, let’s jump straight into some web project ideas that will strengthen your base and allow you to climb the ladder. 1. One-page layout This website ideas for projects aims to recreate a pixel-perfect design and make a one-page responsive layout. This is also a beginner-level project that allows freshers to test their newly acquired knowledge and skill level. This is one of the most basic website development projects that allow beginner-level learners to practice their understanding of HTML, CSS, and possibly introductory JavaScript concepts by implementing the design, structuring the webpage’s content, styling elements, and making the layout responsive. Creating a pixel-perfect and responsive one-page layout encourages beginners to focus on fundamental concepts such as layout structuring, styling techniques, media queries for responsiveness, and overall design consistency. It provides hands-on experience in translating a static design into a functional web page while honing their understanding of essential web development principles. You can use the Conquer template to build this project. This template comes loaded with a host of unique layouts. Also, it brings before you a series of challenges that Web Developers often face in real-world scenarios. As a result, you are pushed to experiment with new technologies like Floats and Flexbox to hone the implementation of CSS layout techniques. Get Advanced Certification in Cloud Computing from IIITB 2. Login authentication  Login authentication is a vital process, widely followed by organizations to keep their servers safe by allowing access only to authenticated users. Every website or application demands users to complete the login authentication process to cement their credentials for security and to improve user experience. Working on login authentication web development projects for final-year students is an excellent way to improve one’s development skills. This is a beginner-level web projects, that is great for honing your JavaScript skills. In this project, you will design a website’s login authentication bar – where users enter their email ID/username and password to log in to the site. Since almost every website now comes with a login authentication feature, learning this skill will come in handy in your future web projects and applications. Working on these basic web development projects will give you hands-on experience dealing with authentication workflows, security protocols, and backend integration. This will help you understand the complexities and considerations of creating secure login systems. Moreover, these projects will enable you to hone your critical thinking, problem-solving skills, and precision, all crucial skills in web development and cybersecurity. Ultimately, undertaking login authentication website development projects provides an excellent platform for final-year students to apply theoretical knowledge, enhance practical skills, and gain a deeper understanding of security and user authentication in real-world web applications. Learn Software development Courses online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career. 3. Product landing page Being the face of any website, a product landing page has the ability to target customers more than any other aspect through its visuals and various other compelling features. Designing a product landing page is vital for web developers to test practical skills and how convincing they actually are. Aspirants exploring web app project ideas must take up this interesting web development project for final-year students to learn in-depth what customers demand and how visuals can grab their attention. Designing a compelling product landing page is one of the best project ideas for web development. It is essential for web developers as it allows them to test their practical skills in creating persuasive and visually appealing web content.  To develop a product landing page of a website, you must have sound knowledge of HTML and CSS. In this project, you will create columns and align the components of the landing page within the columns. You will have to perform basic editing tasks like cropping and resizing images, using design templates to make the layout more appealing, and so on.  Product landing page designing can be ideal for web projects for final-year students. It can help them gain practical insights into user psychology and the importance of meeting customer demands in the digital market landscape. It provides a holistic learning experience combining design aesthetics, user engagement strategies, and technical implementation, preparing students for real-world challenges in web development and digital marketing. Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript Read: Full Stack Project Ideas & Topics 4. Giphy with a unique API This web development projects for final-year involves developing a web application that uses search inputs and Giphy API for presenting GIFs on a webpage. This is an excellent beginner-level project wherein you use the Giphy API to recreate the Giphy website. We recommend you use the Giphy API since you need not request any API key to use it. Another advantage of using the Giphy API is that you don’t require to worry about configuration while requesting data.  If you want to hone your API skills, this should be one of your go-to ideas. As one of the highest sought-after web development project ideas for beginners, it introduces students to the concept of API integration, where they learn how to make requests to external APIs, retrieve data (in this case, GIFs) based on user input, and display it dynamically on a webpage. You can use the Giphy API to build a web application that has a search input where users can search for specific GIFs, can display trending GIFs in a column/grid format, and has a load more option at the bottom for searching more GIFs. Also, Check out online degree programs at upGrad. 5. JavaScript quiz game This web development projects ideas for final year students aims to create a JavaScript quiz game that can take multiple answers and show the correct result to users. While gaining JavaScript knowledge isn’t tricky, applying that knowledge in real-world scenarios is usually challenging. However, you can use a small JavaScript-based quiz game to experiment with your skills. While building this web projects, you will deal with complex logic and learn a lot about data management and DOM manipulation. Depending on your JavaScript skills and ability to handle complex logic, you can make the game as simple or complicated as you want it to be! upGrad’s Exclusive Software and Tech Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4 This is undoubtedly the best project for web development directed to final-year students looking to enhance their JavaScript skills by practically applying them to create a dynamic and interactive quiz game. They’ll gain a deeper understanding of handling data, manipulating the DOM, managing user interactions, and implementing complex logic, all fundamental aspects of modern web development. Moreover, the flexibility of the project allows students to tailor the complexity of the game based on their skills, allowing for both beginner-friendly and more challenging implementations. 6. To-do list One of the most common web development projects ideas for final year is the one every web developer must practice through web app project ideas to create a web development project comprising various features essential for daily life. To-do lists contain user-interactive features with basic features like adding or removing tasks, highlighting dates, strikethrough features to indicate completion, and other text decoration components. This project offers a comprehensive learning experience for final-year students in web development. It requires them to apply their understanding of HTML for structure, CSS for design and layout, and JavaScript for creating interactive functionalities.  Deemed as one of the best website project ideas, it allows them to grasp essential concepts like event handling, DOM manipulation, and local data storage while building a practical tool that many users find beneficial in managing their daily tasks.  You can use JavaScript to build a web app that allows you to make to-do lists for routine tasks. For this project, you must be well-versed in HTML and CSS. JavaScript is the best choice for a to-do project since it allows users to design interactive coding lists where they can add, delete, and also group items.  Overall, the to-do list web application project serves as an excellent platform for you to showcase your skills in creating a functional and user-friendly web app. Also read: Full Stack Developer Salary in India 7. SEO-friendly website Today, SEO is an integral part of website building. Without SEO, your website will not have the visibility to drive traffic from organic searches in SERPs (search engine result pages). While Web Developers are primarily concerned about website functionality, they must have a basic idea of web design and SEO. In this project, you will take up the role of a Digital Marketer and gain in-depth knowledge of SEO. It will be helpful if you are aware of the technical SEO for this project. When you are well-versed in SEO, you can build a website having user-friendly URLs and featuring an integrated, responsive design. This will allow the site to load quickly on both desktop and mobile devices, thereby strengthening a brand’s social media presence. Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses 8. JavaScript drawing Infinite Rainbow inspires this web project ideas on CodePen. This JavaScript-based project uses JavaScript as a drawing tool to bring to life HTML and CSS elements on a web browser. The best thing about this project is that you can use JavaScript’s supercool drawing libraries like GoCanvas, Canviz, Raphael, etc. By working on this web project ideas you can learn how to use and implement JavaScript’s drawing capabilities. This skill will come in handy for enhancing the appeal of static pages by adding graphical elements to them. 9. Search engine result page This projects on web development is super interesting and exciting! In this project, you must create a search engine result page resembling Google’s SERPs. While building this project, you must ensure that the webpage can display at least ten search results (just like Google). Also, you must include the navigation arrow at the bottom of the webpage so that users can switch to the next page. This is one of the best web development projects for beginners. This allows you to have an immersive practical experience and learn about data fetching, dynamic content display, pagination, responsive design, user interface design, and enhancing user interaction. Additionally, web technology projects like these will encourage you to explore APIs, understand the intricacies of mimicking existing interfaces, and gain insights into the complexities of search result presentation. Ultimately, successfully building a SERP-like webpage showcases proficiency in front-end development and demonstrates the ability to create functional and user-centric web applications. 10. Google home page lookalike Another interesting JavaScript project on our list, this project requires you to build a webpage that resembles Google’s home page. Keep in mind that you have to build a replica of Google home page along with the Google logo, search icons, text box, Gmail, and image buttons – basically, everything that you see on Google’s home page. This should be relatively easy, provided you are proficient in HTML and CSS. Since the aim here is to build a replica of Google’s home page, you need not worry too much about the functionality of the components of the page. 11. Tribute page Yes, tribute pages are a real thing. If you Google “tribute page,” you will find a comprehensive list of links showing you how to build tribute pages. Essentially a tribute page is a webpage dedicated in honor of someone you love, admire, or respect. It can be a person or a beloved pet.  A tribute page is a perfect project for sharpening your HTML and CSS skills and knowledge. In this projects on web development you will make a webpage to write and dedicate a tribute to someone and publish the same. Apart from the write-up for the tribute, you need to add relevant images, links, etc., on the page. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses 12. Survey form Building a survey form or questionnaire is easy if you are proficient in HTML or HTML5. Even today, lots of companies use survey forms as a means of collecting relevant data about their target audience.  In this web development project ideas, you must design a full-fledged survey form that includes relevant questions like name, age, email, address, contact number, and other questions, depending on the type of company or organization you are shaping the form. This project will put to the test your webpage structuring skills. With this project, students can learn the ins and outs of structuring and designing a comprehensive survey form using HTML or HTML5. They learn about form elements, input types, validation, semantic HTML, accessibility considerations, and user interface design, fundamental aspects of web development. Moreover, this project allows students to understand the importance of user data collection for businesses or organizations and how to create a user-friendly interface for gathering valuable information. Overall, designing a survey form provides hands-on experience in webpage structuring and is a significant step toward becoming proficient in front-end development. 13. Exit the plugin In this website ideas for projects, you will design an exit widget or plugin. When you visit a website or a webpage, you must have seen the tiny pop-ups on the screen when you wish to exit the site/page. Companies usually use exit plugins to show exciting offers to keep users on the page. This is precisely what you have to design. Website development projects like these challenge students to apply JavaScript skills in detecting user behavior and creating a dynamic and engaging exit widget. It allows them to explore user interaction patterns, content personalization, and the psychology behind retaining user interest on a webpage. You can use your JavaScript and skills to design unique exit plugins wherein the content will be customized based on how long the user stays on a page. Implementing an effective exit plugin successfully demonstrates proficiency in front-end development and user experience enhancement. This makes this one of the best website project ideas for students to develop essential skills in this field. 14. Note log This web development mini projects will be much like the to-do list we mentioned above. The aim is to design and build a notes app that can take multiple entries per note. It should allow users to select a note when they launch the app. When they choose a note, a new entry will be automatically tagged along with the current date, time, and location. Users can also sort and filter their entries based on this metadata.  This project offers a practical learning experience in web development, requiring you to apply your HTML, CSS, and JavaScript knowledge to create a functional and user-friendly note app. It allows you to explore various JavaScript functionalities, data management, user interface design, and interaction while efficiently addressing the real-world problem of organizing and tracking events. This is a great web app for tracking events and resolving messy calendar problems. As one of the best web development projects ideas for final year students, the Note Log project will encourage you to think about user needs and how technology can be used to solve practical problems. This makes it a brilliant exercise in both technical skills and problem-solving abilities in web development. 15. Social share buttons Most websites (particularly, content-based ones) built on WordPress have social share buttons that allow users to share content on various social media platforms. However, for static sites that aren’t based on WordPress, adding social share buttons is a challenge. In this project, you will take up the challenge of writing JavaScript code that will allow you to add social share buttons to static sites. While you can do this by incorporating HTML elements or images in the site’s template, using JavaScript allows you to add the share buttons dynamically. Among the best web development project ideas for beginners, it trains students in DOM manipulation, handling external APIs or URLs for social media interactions, and enhancing user engagement by enabling easy content sharing.\ Moreover, this project allows freshers to explore customization options, user interaction patterns, and design considerations for integrating external functionalities into a website, providing valuable insights into front-end development and user experience enhancement. 16. Toast notifications A toast notification is an unobtrusive and non-modal window element that is used to display brief, auto-expiring information to users. You can see toast notifications primarily on Android OS platforms. In this web development project ideas, you must design a toast notification tool. Using your JavaScript skills and knowledge, you’ve to create a functional toast notification tool that can respond to events on the page and notify the users as and when an event has been completed successfully. You could also use the setTimeout function to represent the delay in loading or saving data. 17. AJAX-style login This web development mini projects focuses on building the front end of an AJAX-style login site/page. In AJAX-style login, the login page does not need to be reloaded to ensure whether or not you have to input the correct login details. If you want, you can also create a mockup of both successful and invalid login situations by hard-coding a username and password and comparing this to the information entered by a user. You can also include error messages for situations where the input data is incorrect or not found. As one of the most basic web projects to choose from, you will gain hands-on experience in implementing AJAX for handling login requests. You will also better understand client-server communication and how to dynamically update webpage content without page reloads. Web technology projects like these provide a practical approach to enhancing user experience by creating a more responsive and seamless login process. Additionally, this project demonstrates proficiency in front-end development and interaction with server-side components—a valuable skill set in web development. 18. Word Counter This is a nifty tool for people who write detailed documentation, blogs, essays, etc., online. A word counter tool allows you to see how many words you’ve written so far and how much more you need to write.  This is a pretty simple project which requires you to build an application that can parse texts and show the number of words and characters contained in a write-up. You can also include additional functionality in the word counter to provide more advanced information such as the number of passive sentences in a block of text. 19. Countdown timer Another simple project on our list is a countdown timer or clock. For this project, you just need to create a simple webpage that can update the time every second. With JavaScript as its foundation, you can make the page more appealing by including start, stop, and pause buttons on the page. Students will create the basic structure of the webpage using HTML, defining elements to display the current time and buttons for start, stop, and pause functionalities. Styling the webpage using CSS allows students to design an appealing and user-friendly interface. They can customize the timer’s appearance, buttons, and overall layout to make it visually appealing. By working on basic web development projects like these, students gain practical experience in using JavaScript to create dynamic and interactive elements on a webpage. They learn about manipulating the Document Object Model (DOM), handling events, and updating content in real-time—a fundamental aspect of modern web development. Moreover, adding user interaction features like start, stop, and pause buttons elevate the project’s complexity, allowing students to delve deeper into handling user inputs and implementing functionality based on those interactions. Overall, this simple countdown timer or clock project is an excellent starting point for beginners to explore JavaScript and create interactive web elements. 20. Modal pop-ups This project ideas for web development is very similar to the social share button project. Here, you need to create a JavaScript code that will be immediately triggered every time a user clicks a button on or loads the page. You will design modal pop-ups to provide notifications, promotions, and email signups to users. The pop-up should be such that it can be closed with a click as well. To make the project more challenging, you can experiment with different animations and modal entrances like fade-in and slide-out. By working on website project ideas like these, students can gain practical experience in using JavaScript to create dynamic and interactive modal pop-ups. They learn about event handling, DOM manipulation, and improving user engagement by delivering targeted messages or prompts. Moreover, this project allows students to work with various design elements and interaction patterns, enhancing their front-end development and user interface design skills. 21. Address book In this web development projects for students you must build an application to search for particular entries in your address book by filtering the attributes you specify. You can either use an API that generates placeholder data, or you can also structure the JSON (JavaScript Object Notation). Once the data is in place, you must load it in your application by using an AJAX request (jQuery or XML HTTP request) just as you would in a real-world application. Also, you can design the web application to cache requests in the local storage to avoid unnecessary network requests. Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? What are the uses of Web Development? Web development projects have a wide range of uses and applications for individuals and businesses. Here are some of the key uses of web development: Creating Websites Web development primarily aims to create websites that serve as online representations of individuals, businesses, organizations, or causes. Websites can provide information, showcase products or services, promote events, and more. E-Commerce Web development is essential for creating online stores and e-commerce platforms. These platforms allow businesses to sell products and services directly to customers over the Internet, reaching a global audience. Web Applications Web development is used to create various web applications offering specific functions and services. Examples include online banking systems, project management tools, social media platforms, and email services. Blogs and Content Management Web development enables the creation of blogs and content management systems (CMS) like WordPress, allowing individuals and organizations to easily publish and manage articles, posts, and other content. Online Learning Platforms Web development is crucial for building e-learning platforms where users can access educational content, courses, and interactive lessons online. Social Networking Social networking websites and platforms like Facebook, Twitter, and LinkedIn rely on web development to provide user profiles, communication features, and sharing functionalities. Entertainment and Media Websites and web applications are used for streaming videos, music, and other forms of entertainment. Platforms like YouTube, Netflix, and Spotify are examples of web development in the entertainment industry. Booking and Reservation Systems Web development is used to create platforms for booking flights, hotels, restaurants, and other services. These systems allow users to make reservations and manage their bookings online. Healthcare and Telemedicine Web development creates telemedicine platforms and healthcare applications that enable remote medical consultations, appointment scheduling, and health tracking. Real Estate and Property Listings Real estate websites and platforms use web development to display property listings, provide virtual tours, and facilitate communication between buyers, sellers, and agents. Government and Public Services Government websites offer various services online, such as tax filing, permit applications, and information dissemination. Web development is integral to these platforms. Portfolio and Personal Websites Individuals, artists, photographers, writers, and professionals often use web development to showcase their work, skills, and achievements through personal websites or portfolios. News and Media Outlets Online news publications and media outlets use web development to deliver their audiences up-to-date news, articles, videos, and multimedia content. Collaboration and Communication Tools Web development creates tools and platforms for remote collaboration, communication, and teamwork, such as video conferencing apps, project management tools, and messaging platforms. Looking to challenge yourself or expand your portfolio? Check out our curated list of computer science project ideas to inspire your next groundbreaking project. Conclusion These are our top web development projects for students and web development projects with code for final-year students and freshers. All the projects mentioned in our list are relatively easy; hence, they are excellent for freshers who’ve just started in the web development world. However, always choose project ideas for web development according to your skill level. Start by working on beginner-level projects and gradually move to advanced JavaScript projects. Working on these projects will expand your skill set and enhance your professional portfolio. A comprehensive combination of a professional adept in all layers of an engineering process is always a demand in businesses aimed at expansion. Companies and fellow professionals alike, highly value Full-Stack Developers. With the surplus of knowledge in hand, there is an evident shift in demands for professionals who adapt quickly to changing requirements, thus proving their mettle. With the world experiencing an increase of around 3.2 million developers globally, reports expect the number to grow further to about 8.7 million people by 2024, cementing opportunities and a bright future for web developers worldwide.  If you’re interested to learn more about full-stack development, check out upGrad & IIIT-B’s Executive PG Program in Full-stack Software Development which is designed for working professionals and offers 500+ hours of rigorous training, 9+ projects and assignments, IIIT-B Alumni status, practical hands-on capstone projects & job assistance with top firms. 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by Arjun Mathur

18 May 2024

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Java Interview Questions & Answers In this article, we have compiled the most frequently asked Java Interview Questions. These questions will give you an acquaintance with the type of questions that an interviewer might ask you during you interview for Java Programming As a fresher, you have either just attended an interview or planning to attend one soon. An Entry Level jobseeker looking to grow your career in software programming, may be nervous about your upcoming interviews. All of us have those moments of panic where we blank out and might even forget what a thread is. We will simplify it for you, all you need to do is take a deep breath and check the questions that are most likely to be asked. Check out our free courses related to software development. Embrace the opportunity to showcase your passion for software programming. These carefully curated interview questions encompass core Java concepts, offering a solid foundation to build upon. Whether unraveling the mysteries of threads or delving into fundamental programming paradigms, remember that preparation is vital. Embrace each question as a chance to demonstrate your enthusiasm and potential. With each response, you paint a picture of your capabilities. So, take a moment, absorb these questions, and approach your interview with newfound confidence. Your journey to a fulfilling software programming career begins here. You can’t avoid panicking, but you can definitely prepare yourself so that when you step in that interview room. You are confident and know you can handle anything the interviewer might throw at you. Learn Software engineering programs online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career. Here is a compiled list of comprehensive 24 Java Interview Questions with Answers (latest 2022) that will help you nail that confidence, and ensure you sail through the interview. 1. What all does JVM comprise of? JVM, short for Java Virtual Machine is required by any system to run Java programs. Its architecture essentially comprises of: ● Classloader: It is a subsystem of JVM and its main function is to load class files whenever a Java program is run. ● Heap: it is the runtime data that is used for allocating objects. ● Class area: it holds the class level of each class file such as static variables, metadata, and constant run pool. ● Stack: used for storing temporary variables. ● Register: the register contains the address of the JVM instruction currently being executed ● Execution engine: the EE consists of a virtual processor, an interpreter that executes instructions after reading the bytecode, and a JIT compiler which improves performance when the rate of execution is slow. ● Java Native Interface: it acts as the communication medium for interacting with other application developed in C, C++, etc. Method Area: It is a storage area for compiled code of conventional language.  Native  Method Libraries: The library consists of various lists of programming languages such as C, C++, or more.  Java interview questions and answers like such make for a confident start in any interview. Whenever the interviewer asks you any component-related question, always categorise it and give one line description. This helps in creating a positive impression on the recruiter.  Check Out upGrad Java Bootcamp Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses 2. What is object-oriented programming? Is Java an object-oriented language? Essentially, object-oriented programming is a programming paradigm that works on the concept of objects. Simply put, objects are containers – they contain data in the form of fields and code in the form of procedures. Following that logic, an object-oriented language is a language that works on objects and procedures. The object-oriented programming language consists of classes of objects that is linked with methods (functions) they are associated with.   These concepts of object-oriented programming can contain data and code. The procedures are a common feature of objects that are attached to them. This helps in easy access and modification. Some of the programming languages that consist of OOPs are C, C++, Python,  and Javascript.  Check Out upGrad Full Stack Development Bootcamp Since Java utilizes eight primitive datatypes — boolean, byte, char, int, float, long, short and double — which are not objects, Java cannot be considered a 100% object-oriented language. These types of java interview questions for freshers 2024 will stay relevant and will be asked in the coming times. Stay updated with your answers, and always be prepared to handle these fundamental questions, so brush up on the basics before appearing for your interview. 3. What do you understand by Aggregation in context of Java? Aggregation is a form of association in which each object is assigned its own lifecycle. But, there is ownership in this, and the child object cannot belong to any other parent object in any manner. It helps in reusing code. It builds a relationship between two classes that builds a ‘has-a’ and ‘whole/ part’ relationship. It contains a reference to another class and is said to be having ownership of that class.  These technical-based java interview questions are asked to gauge the depth of your technical knowledge. Make sure not to keep your answers til a bookish definition; rather, mention how the technology is important or useful in the domain. 4. Name the superclass in Java. Java.lang. All different non-primitive are inherited directly or indirectly from this class. It is the ultimate base class for all non-primitive data types, directly or indirectly. This fundamental class provides essential methods like equals(), hashCode(), and toString(), which are throughout Java’s class hierarchy. Extending the Object, classes inherit a standardized interface, facilitating interoperability and enabling features like polymorphism and object comparison. This pivotal superclass embodies the core principles of Java’s object-oriented paradigm, forming the cornerstone of the language’s rich class structure. Understanding its role empowers developers to harness the full potential of Java’s inheritance and abstraction mechanisms. 5. Explain the difference between ‘finally’ and ‘finalize’ in Java? Used with the try-catch block, the ‘finally’ block is used to ensure that a particular piece of code is always executed, even if the execution is thrown by the try-catch block. In contrast, finalize() is a special method in the object class. It is generally overridden to release system resources when garbage value is collected from the object. Before appearing for the interview to tackle these types of java interview questions for freshers, you may refer to the below-mentioned table-  Finally Finalize Used for exception handling Protected method java.lang.object It is a block. It is a method. Can be followed by try-catch/ without it. Can be explicitly called from an application program.` It is used to clean up the resources used in the ‘try’ block. Clean up the activities related to the object before the destruction. 6. What is an anonymous inner class? How is it different from an inner class? Any local inner class which has no name is known as an anonymous inner class. Since it doesn’t have any name, it is impossible to create its constructor. It always either extends a class or implements an interface, and is defined and instantiated in a single statement. A non-static nested class is called an inner class. Inner classes are associated with the objects of the class and they can access all methods and variables of the outer class. Some of the features of an anonymous class include- It is without any name. Only one object is created for it. It is used to override a method of a class.  It can implement only one interface at a time. Our learners also read: Java free online courses! 7. What is a system class? It is a core class in Java. Since the class is final, we cannot override its behavior through inheritance. Neither can we instantiate this class since it doesn’t provide any public constructors. Hence, all of its methods are static. These types of java interview questions for freshers 2024 are relevant and will be asked in the coming times.  Some of the features of system class include One of the core classes in Java. It is a final class and does not provide any public constructors. All members and methods in this class are static. This class cannot be inherited to override its methods. Its purpose is to provide access to system resources. 8. How to create a daemon thread in Java? We use the class setDaemon(true) to create this thread. We call this method before the start() method, and else we get IllegalThreadStateException. Daemon threads provide background support to non-daemon threads, allowing the program to terminate without waiting for them to finish their execution. These threads are useful for tasks like garbage collection or logging, ensuring that essential operations are managed efficiently and enhancing overall performance and responsiveness of Java applications. Daemon threads in Java, marked by setDaemon(true), are crucial in maintaining a well-organized and responsive application environment. Unlike user threads, daemon threads don’t prevent the program from exiting once the main execution concludes. They gracefully terminate alongside the main thread, handling auxiliary tasks seamlessly. By understanding and skillfully implementing daemon threads, developers can optimize resource utilization and enhance the overall user experience, making them an indispensable tool in Java multithreaded programming. If you have more experience, such as ten years, these types of java interview questions for 10 years experience 2024 can be asked.  Job Profile for Software Developer 9. Does Java support global variables? Why/Why not? No, Java doesn’t support global variables. This is primarily because of two reasons: ● They create collisions in the namespace. ● They break the referential transparency. 10. How is an RMI object developed? The following steps can be taken to develop an RMI object: ● Define the interface ● Implement the interface ● Compile the interface and it implementations with the java compiler ● Compile server implementation with RMI compiler ● Run RMI registry ● Run application 11. Explain the differences between time slicing and preemptive scheduling? In the case of time slicing, a task executes for a specified time frame – also known as a slice. After that, it enters the ready queue — a pool of ‘ready’ tasks. The scheduler then picks the next task to be executed based on the priority and other factors. Time slicing is useful for non-priority scheduling. Every running- thread would be used for a fixed period. It is used for a predefined slice of time. Whereas under preemptive scheduling, the task with the highest priority is executed either until it enters dead or warning states or if another higher priority task comes along. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses upGrad’s Exclusive Software and Tech Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4   12. Garbage collector thread is what kind of a thread? It is a daemon thread. It is a low priority thread running in the background.  Operating with lower priority, it discreetly works in the background, automatically managing memory by identifying and reclaiming unused objects. This integral part of Java’s memory management system ensures optimal resource utilization by freeing up memory occupied by objects that are no longer accessible. The daemon nature of the garbage collector thread allows it to coexist harmoniously with other threads, executing its crucial role without delaying or obstructing the program’s primary functionality. This non-obtrusive yet essential thread contributes to Java’s efficiency and robustness, facilitating smoother application execution. 13. What is the lifecycle of a thread in Java? Any thread in Java goes through the following stages in its lifecycle: ● New ● Runnable ● Running ● Non-runnable (blocked) ● Terminated 14. State the methods used during deserialization and serialization process. ObjectInputStream.readObject Reads the file and deserializes the object. ObjectOuputStream.writeObject Serialize the object and write the serialized object to a file. 15. What are volatile variables and what is their purpose? Volatile variables are variables that always read from the main memory, and not from thread’s cache memory. These are generally used during synchronization. The volatile variable is casted with a keyword “volatile” to signify that this variable can be changed by some outside factor.  Some of the key features of the volatile memory- It is a field modifier. Improves thread performance The thread cannot be blocked for being volatile in case waiting.  Not subject to compiler optimisation. 16. What are wrapper classes in Java? All primitive data types in Java have a class associated with them – known as wrapper classes. They’re known as wrapper classes because they ‘wrap’ the primitive data type into an object for the class. In short, they convert Java primitives into objects. Some of the key features of wrapper classes in Java- Convert primitive into object and object into primitive. Contains the feature of autoboxing and unboxing to transform the primitive into objects and vice verca. 17. How can we make a singleton class? By making its constructor private. Some of the other ways of creating singleton class include- Only one instance of class is present.  Declare all constructors to be private. Provide a static method that runs a reference to instance. 18. What are the important methods of Exception Class in Java? ● string getMessage() ● string toString() ● void printStackTrace() ● synchronized Throwable getCause() ● public StackTraceElement[] getStackTrace() 19. How can we make a thread in Java? We can follow either of the two ways to make a thread in Java: ● By extending Thread Class The disadvantage of this method is that we cannot extend any other classes since the thread class has already been extended. ● By implementing Runnable interface. The thread class make performing operations on a thread easier by providing constructors and methods to create. It also facilitates in extending objects class and  implementing runnable interface.  20. Explain the differences between get() and load() methods. The get() and load() methods have the following differences: ● get() returns null if the object is not found, whereas load() throws the ObjectNotFound exception. ● get() always returns a real object, whereas load() returns a proxy object. ● get() method always hits the database whereas load() doesn’t. ● get() should be used if you aren’t sure about the existence of an instance, whereas load() should be used if you are sure that the instance exists. 21. What is the default value of the local variables? They aren’t initialized to any default value. Neither are primitives or object references. There are no default values assigned to the local variables. They should be declared and the initial value should be assigned  before the first use. 22. What is Singleton in Java? It is a class with one instance in the whole Java application. For an example java.lang.Runtime is a Singleton class. The prime objective of Singleton is to control the object creation by keeping the private constructor. Some of the features of Singleton in Java include- A singleton class can have only one object or instance of a class at a time.  Ensures existence of only class in JVM. Must provide global access point to get the instance of  class.  It is used for caching, logging, drivers object, thread pool, etc.  Java interview questions 2024 can be frequently asked in coming times. So do not restrict yourself to one line response, rather mention of few features as well. 23. What is the static method? A static method can be invoked without the need for creating an instance of a class. A static method belongs to the class rather than an object of a class. A static method can access static data member and can change the value of it. A static methods are accessed by their class name, rather than object of class. One significant trait of static methods is their ability to access and modify static data members, promoting efficient data handling. It differentiates them from instance methods that operate within an object’s scope. Utilizing static methods enhances code organization and fosters a modular approach, simplifying the design and maintenance of Java programs by enabling direct class-level interaction. 24. What’s the exception? Exceptions Unusual conditions during the program. This may be due to an incorrect logic written by incorrect user input or programmer. This exception event occurs at an execution of a program disrupting the normal flow of the program’s instructions. There are various types of exceptions in Java such as- Checked exception Unchecked exception  25. In simple terms, how would you define Java? Java is a high-level, platform-independent, object-oriented portal, and offers support with high performance for building sophisticated programs, applications, and websites. Java is a general-purpose programming language that empowers developers to build rich functionality applications with their write once run anywhere (WORA) environment. James Arthur Gosling, a computer scientist from Canada, developed Java in 1991 and is popularly known as ‘Dr Java’. Today, Java has become an essential foundation for the modern IT industry. Read: Must Read Top 58 Coding Interview Questions & Answers 26. What is Java String Pool? A String Pool in Java is a distinct place that has a pool of strings stored via the Java Heap Memory. Here, String represents a special class in Java, and string objects can be created using either a new operator or using values in double-quotes. The String is immutable in Java, thus, making feasibility of String pool and then the further implementation via String interning concepts. 27. What is a collection class in Java? List down its methods and interfaces? Java Collection Classes are special classes, which are exclusively used with static methods that work specifically on return collections. Java Collection by default inherit a class and have two essential features as:  They support and operate with polymorphic algorithms that return new collections for every specific collection. Methods in Java Collection throw a NullPointerException in case the class objects or collections have Null value.   These are represented and declared as Java.util.Collectionclass.   There are more than 60 methods, modifiers, and types of Java Collection classes. Here is a list of the topmost important methods in Java Collection Class:  S. No. Modifier, Method, and Type Description 1. static <T> boolean addAll() This method allows the addition of specific elements to a particular collection. 2. static <T> Queue <T> asLifoQueue() This method allows the listing of the collection as Last-in-first-out (LIFO) in view. 3. static <T> int binarySearch() This method allows searching for a specific object and then returns them in a sorted list. 4. static <E> Collection<E> This method returns the dynamic view from any particular collection. 5. static <E> List <E> This method gives a return of a dynamic typesafe view from a particular list. Here are some examples for Java Collection: Java Collection min() Example: 1 2 3 4 5 6 7 8 9 10 11 12 import java.util.*; public class CollectionsExample { public static void main(String a[]){ List<Integer> list = new ArrayList<Integer>(); list.add(90); list.add(80); list.add(76); list.add(58); list.add(12); System.out.println("Minimum Value element in the collection: "+Collections.min(list)); } } The output will be: Minimum Value element in the collection: 12 Java Collection max() Example: 1 2 3 4 5 6 7 8 9 10 11 12 import java.util.*; public class CollectionsExample { public static void main(String a[]){ List<Integer> list = new ArrayList<Integer>(); list.add(90); list.add(80); list.add(76); list.add(58); list.add(12); System.out.println("Maximum Value element in the collection: "+Collections.max(list)); } } The output will be: Maximum Value element in the collection: 90 Experienced professionals are expected to have an organised answer for these types of questions. You may choose to tackle java interview questions for 8 years experience 2024 in this manner. 28. What is a servlet? Servlets are Java software components that add more capabilities to a Java server via technology, API, interface, class, or any web deployment. Servlets run specifically on Java-powered web application servers and are capable of handling complex requests from the web server. Servlets add the benefit of higher performance, robustness, scalability, portability, and ensure safety for the Java applications.  Servlet Process or Execution: This starts when a user sends a request from a web browser. The web server receives and then passes this request to the specific servlet. The Servlet then processes this request to get a specific response with output. The Servlet then sends this response back to the web server. Then the web server gets the information that the browser displays on the screen.   Java Servlets come with multiple classes and interfaces like GenericServlet, ServletRequest, Servlet API, HttpServlet, ServeResponse, etc. 29. What is Request Dispatcher? In Servlet, RequestDispatcher acts as an interface for defining an object to receive requests from clients at one side and then dispatching it to particular resources on the other side (that may be a servlet, HTML, JSP). This RequestDispatcher has two methods in general:  void forward(ServletRequest request, ServletResponse response) That allows and forwards the requests from any servlet to server resources in the form of a Servlet, HTML file, or a JSP file. void include(ServletRequest request, ServletResponse response) That has content for a particular resource in the form of a response such as HTML file, JSP page, or a servlet. 30. What is the life-cycle of a servlet? Servlet is a Java software component that has the main function to first take the request, then process the request, and give a response to the user in an HTML page. Here Servlet Container manages the life-cycle of a servlet. Here are the main stages: Loading Servlet. Then initialising the Servlet. Handling the Request (invoking service method). Then destroying the Servlet.  Here is a quick diagram showing the life cycle of a Java Servlet: Source Loading Servlet The life cycle for Servlet begins with the loading stage in the Servlet container. Servlet loads in either of the two ways with:           Setting the servlet as a positive or zero integral value. Secondly, this process may get delays, as the container selects the right servlet to handle the request.  Now the containers first load the Servlet class and then build an instance via the no-argument constructor.  Initialising Servlet Next step is to use the Servlet.init(ServletConfig) method to initialise the Servlet for instance JDBC data source. Handling the Request (Invoking Service Method) Here the Servlet takes the client requests and performs the required operation using the service() method.  Destroying the Servlet Now the Servlet container destroys the servlet by performing and completing specific tasks and calling the destroy() method in the instance. 31. What are the different methods of session management in servlets? Sessions track the user’s activity after they login to the site. Session management provides the mechanism to procure information for every independent user. Here are the four different methods for session management in the servlets:   HttpSession Cookies URL Rewriting HTML Hidden field 32. What is a JDBC Driver? Java Database Connectivity (JDBC) here acts as a software component that allows Java applications to communicate with a database.  JDBC drivers have the following four types in the environment: JDBC-ODBC bridge driver Network Protocol driver (Middleware driver) Database Protocol driver (fully Java driver) Native-API driver  33. What is the JDBC Connection interface? Connections define the sessions between the database and Java applications. JDBC Connection interface is part of the java.sql package only and provides session information for a particular database. These represent multiple SQL statements for executing and results in the context of a single connection interface. Here are the main methods for Connections interface: createStatement(): To create a specific statement object for adding SQL statements to the particular database. setAutoCommit(boolean status): To define the connection of a commit mode to a false or true directive.  commit(): That makes all the modifications from the last commit and further releases any database presently held by the specific Connection object.  rollback(): That undoes or rollbacks all the changes done in the past or current transaction and also releases the presently held database in the connection object.  close(): That terminates or closes the current connection and also releases or clears the JDBC resources instantly. 34. Name the different modules of the Spring framework? There are multiple modules in the Spring framework: Web module Struts module Servlet module Core Container module Aspect-Oriented Programming (AOP) Application Context module MVC framework module JDBC abstraction and DAO module OXM module Expression Language module Transaction module Java Messaging Service (JMS) module ORM integration module  These modules are present in groups: Source 35. Explain Bean in Spring and list the different scopes of Spring bean. Beans are one of the fundamental concepts of the Spring framework in managing structures efficiently. In a simple definition, Spring Bean represents the IoC containers that manage the object forming the backbone of applications. Scopes of Spring Bean:  Scopes play a crucial role in the effective use of Spring beans in the application. Scope helps us to understand the lifecycle of the Spring Bean, and they have the following types. S. No. Scope and Description 1. Singleton – By default, Spring bean scope has a singleton scope that represents only one instance for Spring IOC container. This same object gets shared for each request. 2. Prototype – In this, a new instance will be called and created for every single bean definition, every time a request is made for a specific bean.  3. Request – In this scope, a single bean will be called and created for every HTTP request for that specific bean.  4. Session – This scope defines the single bean use for a life cycle in a particular global HTTP session.  5. Global-session – This scope allows a single bean for the particular life cycle for implementing in the global HTTP session.   Note: Last three scopes are applicable in the web-aware Spring ApplicationContext only. Must Read: Why Java is so popular with Developers 36. Explain the role of DispatcherServlet and ContextLoaderListener. While configuring XML based Spring MVC configuration in web.xml file, two declarations of DispatcherServlet and ContextLoaderListener play an essential role in complementing the purpose of the framework.   DispatcherServlet –  DispatcherServlet has the primary purpose for managing incoming web requests for specific matching configured URI patterns. DispatcherServlet acts as the front controller for the core of the Spring MVC application and specifically loads the configuration file and then initialises the right beans present in that file. And when annotations are enabled, then it can also check and scan the configurations and packages for all annotated with @Repository, @Component, @Service, or @Controller.  ContextLoaderListener –  ContextLoaderListener here acts as the request listener for starting and shutting down root WebApplicationContext. So, it creates and shares the root application context with child contexts by the DispatcherServlet contexts. Applications can only use one entry for the ContextLoaderListener in the web.xml. 37. Explain Hibernate architecture. Hibernate defines a layered architecture that empowers users to operate and perform without knowing the underlying APIs, i.e., Hibernate acts as a framework to build and develop persistence logic independent from the Database software.  Hibernate architecture has the main four layers with:  Java application layer Database layer Backend API layer Hibernate framework layer Elements of the Hibernate Architecture There are several aspects and scope for Hibernate architecture. To learn more about them, you must know about the elements of Hibernate architecture.  SessionFactory: Sessionfactory provides the method to create session objects that are present in the org.hiberate package only. It is thread-safe in nature, immutable, and holds and preserves the second-level cache of the data.  Session: Session objects provide the interface for Connection and Database software via the hibernate framework.  Transaction: Interface that aids transaction management and allows a change in the database.  ConnectiveProvider: A part of the JDBC connections, it separates the main application from the DataSource or DriverManager.  TransactionFactory: Represents the factory of the transaction. 38. What is an exception hierarchy in Java? The exception defines the unwanted events that present themselves during the run or execution of the program. Exception disrupts the regular flow of the program. Exception Hierarchy is part of the java.lang.Exception class and comes under the primary Throwable class only. Another subclass ‘Error’ also represents the Throwable class in Java. Though Errors are unusual conditions in case of a failure, still they are not handled or cleared with the Java programs. There are two primary subclasses for exceptional hierarchy in Java with RuntimeException class and IOCException Class.  This unwanted or unexpected event can occur at several times such as compile-time or run- time in an application. 39. What is synchronization? Synchronization in Java defines the capability to manage and control the access of multiple threads to a particular resource. So that, one thread can access a specific resource at the present time. Here, Java allows the development of threads and then synchronizing tasks via the synchronizing blocks.   These Synchronized blocks allow only one thread execution for a particular time and block the other threads until the current thread exits in the block. Here monitors concept is crucial in implementing the synchronization in Java. Once the thread goes in a lock phase, it is termed to enter the monitor. Thus, locking all the other threads unless the first thread has exited the monitor. Synchronization gives the capability to control multiple threads at any resource that is shared. Synchronization becomes usefu for reliable communication between threads as the multiple threads might try to access the shared resources at the same time thus producing results that are inconsistent. 40. What are the features that make Java one of the best programming languages? Here are the top features that make Java for starting your learning curve in the programming world: Simplicity: Java is quite simple to learn and write. Java syntax is in C++ that allows the developers to write programs seamlessly.  OOPS: Java is based on the object-oriented programming system (OOPS), thus, empowering to build code in multiple types of objects with different data and behavior. Dynamic: Java is a complete dynamic language that supports the loading of dynamic classes whenever and wherever required. And it also has comprehensive support for native code language such as C, C++, etc. Platform Independent: Java also supports exclusive and platform-independent programming language, thus, allowing developers to run their program on their platform only. Portability: Java has a reach once write anywhere approach that allows the code to run on any platform.  Security: Following the concept of ByteCode, exception handling, and no use of any explicit pointers makes Java a highly secured environment.  Java is also architect neutral with no dependency on any architecture. Strong memory management and automated garbage collection add more robustness to its environment.  41. What makes Java enable high performance? Use of Just in Time (JIT) compiler in its architecture makes Java one of the high performing programming languages, as it transforms instructions into bytecodes. The JIT compiler is helpful in compiling of code on demand. The fast and time efficient features come into play because whichever method is called, only that method block gets compiled. 42. Name most popular Java IDE’s. There are many IDE’s available in the industry for Java. Here are the top five Java IDEs that you can use to start learning this programming language today:  Eclipse Netbeans IntelliJ JDeveloper MyEclipse 43. Define the main differences between Java and other platforms?  Two main differences that make Java stand out from other platforms are: Java is primarily a software-based platform, while others can be either software or hardware-based platforms.  Java runs or executes on any hardware platform, whereas others require specific hardware requirements. You may refer to the below mentioned table to understand the differences between Java and other platforms- Java Other platforms  Software-only platform that runs on top of hardware- based platforms. Other platforms are usually hardware software or hardware only platforms. Java code can be developed n any OS. Other platforms do not have this feature. Java has its own run time environment such as JRE(Java Run-Time Environment) and JVM (Java Virtual Machine) This function is missing on other platforms. 44. What makes Java have its ‘write once and run anywhere’ (WORA) nature? Well, the one-word answer is Bytecode. Java compiler converts all the Java programs into a specific Byte Code acting as a mediator language between the machine code and source code. ByteCode can run on any computer and has no platform dependency.  45. Explain the different types of access specifiers used in Java. In the Java programming language, access specifiers represent the exact scope for class, variable, or a method. There are four main access specifiers: Public defined variables, methods, or classes are accessible across any method or class.  Protected access specifier defines the scope of a class, method, and variable to the same package, within the same class, or to that particular subclass of class.  The Default scope is there for all the present classes, variables, and methods with access to the package only.  The Private scope keeps access of class, variables, and methods to a particular class only.  The access modifiers are mainly used for encapsulation. It helps to control what part of program can access the members of a class to prevent the data misuse.  While tackling questions like such make sure to also make a slight mention of importance of  access modifiers. It gives an edge during java interview questions and answers for freshers. Read: Java Swing Project 46. Explain the meaning of packages in Java along with their advantages. Packages are a grouping mechanism for similar types (interface, classes, annotations, and enumerations) ensuring the protection of the assets and comprehensive name management.  The packages are used to categorise the classes and interfaces. The categorisation is done for smoother maintenance. The packages are also useful for providing protection.   Here are the advantages of packages in Java: Packages help us prevent naming conflicts when classes of the same name exist in two different packages. Packages aid in making access control systematically.  Build hidden classes to be used by the packages.  Helps in locating related classes for the package. Provides access protection.  Reuse classes Provide controlled access Implement data encapsulation Easy search 47. How would you define Constructor in Java? Constructors are a special block of codes that initialises an object in the time of creation. Though it has a resemblance to instance method, still Constructors are not the method, as they don’t have any explicit return type. So every time an object is being created in the system, there is one constructor called for that to execute. If there is no constructor defined, then the compiler uses a default constructor.  Here is a simple presentation of Constructor in Java: 1 2 3 4 5 6 public class MyClass{ //This is the constructor MyClass(){ } .. } 48. What are the different types of constructors used in Java? There are three types of constructors used in Java:  Default Constructor: When a developer doesn’t use a constructor, Java compiler adds a more specific default constructor existing in the .class file.  No-argument Constructor: In this case, there are no arguments in the constructor and the compiler doesn’t accept any parameter, as instance variable method gets initialised with specific fixed values.  Parameterized Constructor: In this case, one or more parameters are present in the constructor written inside the parentheses of the main element only. 49. What are the differences between constructors and methods? The main difference in the constructors and methods are:  Purpose: Constructors aim is to initialize the object of a class whereas method performs specific tasks on code execution.  The method has return types while constructors do not. In Methods, there are abstract, static, final, and synchronization while in constructors, you can’t make specific procedures. You may refer to the below mentioned table for differences- Constructors Methods It is used to create and initialise the object. It is used to execute statements. Invoked implicitly by the system. Invoked during the program code.  Gets executed only when object is created.  Can be executed on beng explicitly called.  Name is same as the class name. Name will not be same as the class name.  Should not have return type.  Should have return type. 50. Explain the meaning of Local variable and Instance variable? Local variables are present in the method, and the scope exists within the method only.  Instance variables are present and defined in the class only with their scope across the class.  51. Explain the meaning of Class in Java? In Java, all the codes, variables, and methods are defined in the class.   Variables represent attributes that define the state of a particular class. Methods represent where business logic takes its effect. Methods include a set of statements and instructions to match the requirements. Here is a simple example for a class in Java: 1 2 3 4 5 6 7 public class Addition{ //Class name declaration int x = 10; //Variable declaration int y= 10; public void add(){ //Method declaration int z = a+b; } } 52. Explain the meaning of Object in Java? Objects are defined as an instance of a class only with specific state and behavior. For example, a dog with a specific state of name, breed, and colour while behavior includes barking, wagging the tail, etc. So anytime JVM reads any new() keyword then a corresponding instance will be created. An object needs to be first declared, then instantiated and finally initialized for performing further. Each object has its own identity, behavior and state.  The state is stored in fields (variables), methods (functions) showcase the objects behavior.  53. Define the default value for byte datatype in Java language. For the Byte data type, the default value is 0.   54. Why is byte data type more beneficial in Java? As byte data type is almost four times smaller than an integer, so it can store more space for large arrays.  They can also be used in place of int, where their limits help to clarify the code. 55. Explain the OOPs concepts in Java. OOPs, are the fundamental concepts of the Java programming language. These include abstraction, polymorphism, inheritance, and encapsulation. Java OOPs concepts empower developers to create variables, methods, and components that further allow them to reuse them in a customised way while maintaining security.  Abstraction- This is useful for hiding internal details. It is also useful to show functionality. Polymorphism- It is when an object behaves differently in different situations. There are two types of polymorphism run-time and compile-time polymorphism. Inheritance- It is when an object acquires the properties and behaviours of another object. The object whose quality gets inherited is called a superclass. The object inheriting the properties is called a sub-class.  Encapsulation- It is used for binding/ wrapping a code and data together in a unit. Access modifier keywords are also used in this process.  56. Explain the meaning of Inheritance. In Java, Inheritance is a specific mechanism that allows one class to acquire the properties (with fields and methods) of another class. Inheritance is one of the basic concepts of Java OOPs.  Inheritance makes it possible to build new classes, add more fields and methods on the existing classes for reusing them in any way.  A subclass is the one that inherits the properties of the other class.  Superclass is the one whose properties are inherited. Some of the properties of inheritance include- Allows to create of a new class from the existing class. The object acquires all the properties of the object it is inheriting from. The methods can be reused of the superclass. New methods and fields can be added to the current class.  Inheritance in java can be used for method overriding.  57. Explain the concepts of Encapsulation in Java? As one of the primary concepts of Java OOPs, Encapsulation empowers the wrapping of data and code within a single unit only. Encapsulation is also known as Data hiding, with variables of a specific class hidden from all other classes and accessible with the methods from the existing class only.  The two essential things for achieving encapsulation in Java are: Declaring the variables of a specific class as a private. Leveraging public setter and getter methods for making changes and viewing the variable values. Some of the other properties of encapsulation include- The code and data(variables) acting upon methods are integrated into a single unit.  Other classes cannot access the variables that have been encapsulated.  Only the methods of the class can access. 58. Explain the concepts of Polymorphism. Polymorphism in Java allows developers to perform a single task in multiple ways. There are two types of Polymorphism in Java with Runtime and Compile time. You can use overriding and overloading methods to operate Polymorphism in Java.  Some of the properties of polymorphism include-  There are different types of polymorphism, such as Static and Dynamic.  Polymorphism allows having various forms of objects, variables and methods.  The behavior is dependent on the type of data that has been used in operation.  59. Explain the meaning of interface. In Java, we cannot achieve multiple inheritances. Here, interface plays a crucial role in overcoming this problem to achieve abstraction, aid multiple inheritances, and also supports loose coupling. Now we have a default, static, and private method in interface with the latest Java updates.  Benefits of interface- Specify the behaviour an object must implement. It acts as a contract between an object and its code. They help in making implementation changes easier. They act as connecting points between modules. 60. What is meant by Abstract class? Abstract classes are built with a specific abstract keyword in Java. They represent both abstract and non-abstract methods.  Benefits of abstract classes- Helps in reducing the complexity of viewing the things. Increases the security of an application. Avoids code duplication. It increases the code reusability. It has the ability to independently change the internal implementation of the class without affecting the user badly. 61. Explain the Abstraction Class in Java? Abstraction is one of the essential properties for hiding the implementation information from the user and then representing the user functions only. For instance, when you send an SMS from one person to another person. The user gets to know only the message and number while the backend process remains hidden. You can achieve abstraction in Java using the following two ways: Abstract Class (0 to 100%) Interface (100%) 62. Explain the difference between Abstraction and Encapsulation in Java. Here are the main differences:                        Abstraction Encapsulation Abstraction aims to gain information. Encapsulation’s main aim is to contain or procure information. In the abstraction process, issues or problems are handled at the interface/ design level. In Encapsulation, problems are handled at a specific implementation level. Abstraction aids in hiding unwanted information. Encapsulation method applies hiding data within a single unit. Implemented with interfaces and abstract classes. Implemented with a particular access modifier (public, private, and protected). Use abstract classes and interfaces to hide complexities. Use getters and setters to hide data. Objects that extend to abstraction must be encapsulated. An object for encapsulation must not be abstracted.  63. Explain the differences between Abstract class and interface. Abstract Class Interface Abstract Class comes with a default constructor. The interface doesn’t have a constructor. So, no further process. Uses both Abstract and Non-Abstract methods. Only use Abstract methods. Classes that must extend for Abstract class need only abstract methods throughout their sub-class. Classes that extend to interface must provide implementation across all the methods. These include instance variables. The interface presents constants only. 64. Explain the main differences between Array and Array List. Array Array List The size needs to be defined for the declaring array. String[] name = new String[5] No size requirements; and modifies dynamically. ArrayList name = new ArrayList You must specify an index for putting an object inside the array. name[1] = “dog”   There are no index requirements.   name.add(“dog”) Arrays are not parameterised. From Java 5.0 onwards, ArrayLists have a specific parameterised type. 65. Explain the difference between static method and instance method. Static or Class Method Instance Method You must declare a method static for a static method. All methods with declaration as static come under Instance method only. No requirements for creating objects in the Static method. The object is a must for calling the instance method. You cannot access Instance or Non-static methods in the static context. You can access both static and non-static in the instance method. Status methods are used to perform a single operation.  Instance methods are used to perform repetitive operations.  The static must be accessed with a repetitive class name. The instance method must be accessed with a repetitive object name. They are alternatively called Class Level Data Members. They are alternatively called Object Level Data Members. 66. How to make Constructors static? Constructors invoked with the object, and static context is part of the class, not the object. Hence, constructors cannot be static and show compiler error if run or executed.  Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? 67. Explain the use of ‘this’ keyword in Java? In Java, ‘this’ keyword represents a specific reference on the current object. There are multiple uses for this keyword for referring to the current class properties from a variable, constructors, methods, and more. You can also pass this as an argument within constructors or methods. You can also fetch this as a return value from the current class instance. You can also refer to this as a static context.  Also Read: How to Code, Compile and Run Java Projects Some of the uses of this keyword include- Can be used to invoke the current class constructor. Can be used as an argument in the method call. Can be used to refer current class instance variable. Can be used to invoke the current class method implicitly. Can be used to return current class instance from method. 68. What is a classloader in Java? What are the different types of ClassLoaders in Java?  Java Classloader’s main function is to dynamically load all classes into the Java Virtual Machine (JVM). ClassLoaders are part of the JRE only. So every time we run a Java program, classloader loads the classes to execute this program. A single ClassLoader loads only a specific class on requirements and uses getClassLoader() method to specify the class. These classes are loaded by calling their names, and in case these are not found then it retrieves or throws a ClassNotFoundException or NoClassDefFoundError.   Java ClassLoader uses three principles in performing tasks with delegation, uniqueness, and visibility. There are three different types of Java ClassLoader:  BootStrap ClassLoader:  BootStrap ClassLoader represents the parent or superclass for extension classloader and all other classloaders. It has machine code that loads the pure first Java ClassLoader and takes classes from the rt.jar and also known as Primordial ClassLoader.  Extension ClassLoader:  Extension ClassLoader represents the child classloader for the superclass or BootStrap ClassLoader. It loads core java classes from jre/lib/ext, i.e., JDK extension library.  System ClassLoader:  Application or System ClassLoader are further child classes of Extension ClassLoader. It takes and loads a file from the current directory for the program that you can customise with the ‘classpath’ switch. 69. Explain the meaning of Java Applet. Java Applet is a program that executes or runs in the web browser only. Applets are specifically designed to function and embed with HTML web pages. Applets have the capability to function full Java applications with the entire use of Java API. JVM is a must requirement to view an applet on the browser. Applet extends with the use of java.applet.Applet class. 70. What are the types of Applets? Based on location, there are two types of Java applets as Local Applets that are stored on the same computer or system. The Remote Applets that have files on remote systems. 71 What are immutable objects in Java? In Java, immutable objects are the ones whose state does not change after it has been created. Immutable objects are ideal for multi-threaded applications that allow sharing the threads while avoiding synchronization. Immutable objects are preferred for building simple, sound and reliable code to match with an effective strategy.  Some of the benefits of immutable objects in Java include- Safety of threads Prevention of identity mutation. Brings ease of caching Supports referential transparency Protection from the corruption of existing objects 72. What do you mean by JRE (Java Runtime Environment)? Java Runtime Environment is the software layer that provides support for minimum requirements to run Java programs on a machine. Along with JDK and JRE, these three constitute the fundamental for running and developing Java programs on a specific machine.  Java Runtime Environment importance- Communicates between Java program and the operating system. Acts as a translator and facilitator. Has the ability to run on any operating system without modifications. It provides an environment for Java programs to be executed. 73. What is a JDK part of? Java Development Kit (JDK) is one of the primary technology packages essential for running Java programs. It can be the implementation from any one of the Java platforms, Standard Edition, Micro or Enterprise edition developed by Oracle for building applications on Windows, Linux, or macOS. 74. What is a Java Virtual Machine (JVM)? Java Virtual Machine (JVM) is one of the three fundamental requirements for running and executing Java programs along with JDK and JRE. JVM has two primary functions; first, to empower Java programs to seamlessly run on any machine or system and second to optimise memory to deliver performance. Java Virtual Machine features- Code compatability. The application can be run anywhere, as it supports (Write Once Run Anywhere). Garabage Collection Compile Control Supports Native Memory Tracking Facilitates Class Data Sharing  Helps in Signal Chaining 75.What are the differences between JDK, JRE, and JVM? JVM JRE JDK Java Virtual Machine Java Runtime Environment Java Development Kit Platform dependent with several software and hardware options available. Software layer that provides support for minimum requirements to run Java programs on a machine. Standard Edition Enterprise Edition Micro Edition   Three notions as: Specification Implementation Instance Set of libraries + files that empower JVM on runtime. JRE + development tools Provides runtime environment for execution. JRE represents the implementation of JVM. Software development environment. 76. How many types of memory areas are there in JVM? There are several types of memory areas in JVM: Class Area: This memory stores pre-class structures with the field, pool, method data, and code.  Heap stands for runtime memory specifically allocated to the objects.  Stack represents the frame’s memory with a local variable, partial results, thread, and a frame for each method. Program Counter Register stores the information for current instruction with the Java Virtual machine execution.  Native method Stack stores all the present native methods being used in the current applications.  77. What is Data Binding in Java? Data binding represents the connections between class and method, field, variable, constructors, or a method body. Java can handle data binding both statically and dynamically. It binds the data to one object or more to ensure synchronisation.  Allows to effortlessly communicate across views and data sources. Handles binding either statically or dynamically. 78. What are the different types of data binding in Java? There are two crucial types of data binding in Java. Static Binding happens at compile time using static, final, and private methods; also known as early binding.  Dynamic Binding presents at runtime with no exact information known about the right method during the compile time. Refer to the below table for static and dynamic binding difference- Static Binding Dynamic Binding Occurs at Compile Time Occurs at Runtime High speed Low speed Known as early binding Known as late binding Not use of actual object Use of actual object Can take place using normal functions.  Can take place using virtual functions. 79. What is a Java Socket? Sockets help in building communication mechanisms from the two computers via TCP. Sockets are ideally more sufficient and flexible for communications.  Features of Java Socket- A java socket point facilitates two-way communication link between two points. It is bound to a port number for the TCP layer to identify the application. Establish a connection between a client and a server.  80. Explain the difference between Path and Classpath. Both path and Classpath represent local environment variables. The path provides the software to locate the executable files while ClassPath specifies the location for .class files in the system.  Refer to the below mentioned table to undesratnd the differences between these two-   Path Classpath Environment variable is used by the operating system to find the executable files. Environment variable is used by rhe Java Compiler to find the path classes.  It is used by CMD prompt in order to find files that are binary. It is used by compiler and JVMto find files that are binary. We must place .\bin folder path We must place .\lib\jar file or directory path 81. Is there an abstract method without the use of abstract class? No, for an abstract method to exist in a class, it must be an abstract class.   82. What is the process of making a read-only class in Java? In Java, you can make a read-only class by keeping all the fields private. This specific read-only class will have only getter methods that return private property. It does not allow to modify or change this property as no setter method is available. 1 2 3 4 5 6 7 8 9 //A Read-only class in Java public class Student{ //private data member private String institute ="MKG"; //getter method for institute public String getInstitute (){ return institute; } } 83. What is the process for making a write-only class in Java? In Java, you can also make a write-only class by keeping all the fields private with the implementation of setter methods only. 1 2 3 4 5 6 7 8 9 // A write-only class in Java public class Student{ //private data member private String institute; //setter method for institute public void setInstitute (String institute){ this.institute=institute; } } 84. Explain the way to access a class in another class in Java? In Java, there are two ways to access a class in another class as: Using the specific name: We can access a particular class from a different package by using the qualified name or import that package that contains a specific class.  Using the relative path: Similarly, we can also use the relative path for that package with a specific class. 85. What is Exception Handling? Exception handling represents the mechanism to handle the exception or abnormal conditions during the runtime errors to keep the normal flow of the application. There are three different types of Java Exceptions with Checked Exception, Unchecked Exception, and Error.  Exception handling features- It is a process of responding to unwanted or unexpected events that happens when a computer program runs. Helps to avoid system crashing by handling with events. It is a mechanism that allows Java programs to tackle various situations. There are various ways an exception can be handled such as- Throwing an exception Catching an exception Handling an exception 86. Explain the difference between Checked Exception and Unchecked Exception. Checked Exceptions are classes that further extend throwable classes except for RuntimeException such as SQLException, IOException, etc. Checked Exceptions are handled during the compile-time only.  Unchecked Exceptions are classes that extend RuntimeException such as NullPointerException, ArithmeticException, etc. and are not handled during the compile time. Refer to the below mentioned table to understand the difference- Checked Exception Unchecked Exception Also known as compile time exceptions Also known as Runtime exceptions Propogated  using throws keywords Automatically propagated Occurs when the chances of failure are too high.  Occurs due to programming misfunctionality. Not sub class of run time exception.  Sub class of run time exception.  87. Which is the base class for Exception and Error? Here, the Throwable class represents the base class for Exception and Error. 88. Mention the Exception handling keyword in Java. There are five keywords for handling exceptions in Java are: Keyword Description try This try block defines the block for placing the execution code. This try block is generally followed by the use of either catch or finally. So, they can’t be used alone. catch Catch block’s main aim is to handle the exception. You must use this in combination with try block and then finally in the later stage. finally Finally, block checks the important code of the program that checks whether execution is done or not. throw The main aim of the throw keyword is to throw an exception from the program. throws The throws keyword is mainly used for declaring exceptions and not for throwing an exception. It provides information about occurrence for exception and is applied with a method signature. 89. Explain the importance of the finally block. Here, the finally block has crucial importance in the smooth running of the program. It is always executed whether the exception is handled or not. Finally, the block comes after the try or catch block. In the JVM, the system will always run the finally block before terminating or closing a file. For each try block present, there can be zero or multiple catch blocks, still there can only one finally block.  Some of the other importance of finally block include- Used to execute important code such as a closing file, etc. Always executed regardless of exception handling. Must be the last block of execution in the program. Used for resource de-allocation. Used to put important codes such as clean-up code 90. Is running a finally block possible without a catch block? Yes, a finally block can run followed by either a try or catch block, respectively.  91. Are there any cases for not existing finally block? Finally block does not run or execute in case the program already exists or brings fatal error for aborting the process.  92. Explain the main differences between throw and throws. throw keyword throws keyword It throws an exception. It declares an exception. Checked exceptions can’t propagate with throw only. Checked exceptions can propagate with throws. It is followed by an instance. It is followed by a class. It is used in the method only. It is used with a specific method signature. There are no possibilities for multiple exceptions. Whereas in this procedure, multiple exceptions can be declared. 93. Is there a possibility for an exception to be rethrown? Yes, if an exception exists, then it can be rethrown. 94. Explain about Exception Propagation. The process of exception within the handling procedure is known as exception propagation. For instance, an exception is first handled at the top of the stack and then if it is not caught then the exception drops to the previous method and if not, then it goes down further till either the exception gets caught, or it reaches the bottom of the stack. Checked exceptions by default have no propagation.  Features of exception propagation- Occurs when an exception is thrown from the top of the stack. In case of not being caught, the exception chooses to drop down the call stack of the preceding method. In case of not being caught even then, it gets dropped even more. 95. Explain the meaning of thread in Java. In Java, the way or flow of the execution is known as the thread. So, every program contains one thread termed as the main thread created by the JVM. Developers have the power to define their custom threads by adding and extending the Thread class using the interface.  Benefits of thread in java- Allows the program to operate more efficiently. Can be used to perform complicated tasks without interrupting the other programs. Can be utilised to free up the main thread. Helps to breakup the tasks into smaller units that can be executed simultaneously. 96. Explain the meaning of the thread pool. Java thread pool is a group of multiple threads that are continuously waiting for allocated tasks. Here Thread pools work under the service provider that pulls a thread from this pool and then assign them the task for a specific job. The Thread pool adds more performance and stability to the system. 97. Explain the difference between String and StringBuffer. String StringBuffer String class is immutable in nature. StringBuffer class, on the other hand, is mutable. Strings are slow. StringBuffer otherwise is quite fast. These consume more memory for creating a new instance. These consume less memory with concat strings. Strings allow the comparison of its content, as it overrides the equals() method from the Object class. Whereas the StringBuffer class cannot override the equals() method from the Object class. 98. Explain the difference between StringBuffer and StringBuilder. StringBuffer StringBuilder It is synchronised with safety to threads. It is non-synchronised with no safety to threads. In this, two threads have no call method. In this, two threads can have call methods seamlessly. Lower or less efficient than StringBuilder. More efficient than StringBuffer. 99. What is the way to create an immutable class in Java? In Java, you can create an immutable class by declaring a final class with all its members as final. Let’s take an example to understand this: 1 2 3 4 5 6 7 8 9 10 11 12 public final class Employee{ final String securityNumber; public Employee(String securityNumber){ this.securityNumber=securityNumber; } public String getSecurityNumber(){ return securityNumber; } } 99. What are inner classes? Java Inner classes are defined and declared within an interface or class. Inner classes allow the system to group classes and interfaces logically making them more readable as well as easy to maintain them. Moreover, these classes can access all members of the outer class with methods as well as private data members.  Benefits of inner classes- They are used to develop readable code. Provides easy access Having separate classes can be avoided. All the members can be accessed, including private members. Requires less code to write. 100. What are the main advantages and disadvantages of using Java Inner classes? Main advantages for Java inner classes include: Accessibility to all members from the outer classes. Less code to write. More maintenance and readable code.  The main disadvantages for Java inner classes include: Less support from the IDE.  A high number of total classes.  101. Define the types of inner classes in the Java programming language? Inner classes have three main types:  Member Inner class that specifies a class within the class using the outside method. Anonymous Inner Class for extending the class or specifying the implementation of an interface.  Local Inner Class to create a class within the method.  102. Define a nested class. Nested classes are defined or declared within a class or interface only. A nested class can specifically access all the members of the outer class with methods and private data members too. Here is a simple syntax of a nested class: 1 2 3 4 5 6 class Java_Outer_class{ //code class Java_Nested_class{ //code } } 103. Can you explain the difference between inner classes and nested classes? All inner classes are defined as non-static nested classes. So, inner classes are part of the nested classes only.   You may refer to the below mentioned table to understand the difference-   Inner class Nested class Always associated with the outer class object. Not associated with the outer class object. Do not declare static members. Static members can be declared. Normally main() method cannot be declared. The Main() method can be declared. Static and Non Static members of the outer class can be directly accessed.  Static members of the outer class can be directly accessed. 104. How would you define the meaning of Collections in Java? Collections in Java are a group of multiple objects that present as one unit; primarily known as a Collections of the objects. They are also called a Collection Framework or architecture that provides storing space for objects and further manipulates design for changes.  Here are the main functions performed by the Java Collections: Sorting Searching Insertion  Manipulation  Deletion There are many interfaces and classes that are part of the collections.  105. Which interfaces and classes are available in the collections? Here is the list of the interfaces and classes that are available with the collections in Java.  Interfaces: Collection, Queue, Sorted Set, Sorted Map, List, Set, Map Classes: Lists, Vector, Array List, Linked List Sets: Hash set, Tree set, Linked Hash Set Maps: Hash map, Hash Table, TreeMap, Linked Hashed Map Queue: Priority Queue  106. Explain sorted and ordered in relation to collections in Java? Sorted: Sorting allows the group of objects to apply internally or externally to sort them in a particular collection, based on their different properties.  Ordered: Defines the values that are sorted on the basis of the values added in the collection and iterate them in a particular order. 107. Which are the different lists available in the collection? Lists store values based on their index position with the duplication allowed. Here are the main types of lists: Array Lists: Uses the Random Access Interface, provides order collection by the index, not sorted, and offers quick iteration. Here is an example to understand this: 1 2 3 4 5 6 7 8 9 10 11 12 13 public class Fruits{ public static void main (String [ ] args){ ArrayList <String>names=new ArrayList <String>(); names.add (“apple”); names.add (“avocado”); names.add (“cherry”); names.add (“kiwi”); names.add (“oranges”); names.add (“banana”); names.add (“kiwi”); System.out.println (names); } } Output is as follows: [Apple, avocado, cherry, kiwi, oranges, banana, kiwi] With the output, you can check that Array List keeps the original insertion order and also allows duplicates. Though not sorted.  Vector: also uses the Random-access method, are synchronised, and offers support for thread safety. Let us understand this with an example: 1 2 3 4 5 6 7 8 9 10 11 12 13 public class Fruits{ public static void main (String [ ] args){ ArrayList <String>names=new vector <String>(); names.add (“kiwi”); names.add (“oranges”); names.add (“banana”); names.add (“apple”); names.add (“avocado”); names.add (“cherry”); names.add (“kiwi”); System.out.println (names); } } Output is as follows: [kiwi, oranges, banana, apple, avocado, cherry, kiwi] Vector lists follow the original insertion order and also support the duplicates. Linked List: It is also an ideal choice for deletion and insertion, elements are double-linked, but is slow in performance.  Example for Linked list: 1 2 3 4 5 6 7 8 9 10 11 12 13 public class Fruits{ public static void main (String [ ] args){ ArrayList <String>names=new vector <String>(); names.add (“kiwi”); names.add (“oranges”); names.add (“banana”); names.add (“apple”); names.add (“avocado”); names.add (“cherry”); names.add (“kiwi”); System.out.println (names); } } Output is as follows: [Apple, avocado, cherry, kiwi, oranges, banana, kiwi] It also follows the original insertion order and accepts duplicates. 108. What are the main differences between collection and collections in Java? The main differences are as follows: The collection represents an interface while Collections is particularly class only. Collection interface provides multiple functionalities for structuring data as List, Set, and Queue. Whereas Collection class’s main aim is limited to sort and synchronise the elements of the collection.  109. Explain the Priority Queue. Priority Queue defines the queue interface for handling linked lists with the purpose of a Priority-in and Priority-out. Queue generally follows a first in first out (FIFO) algorithm, still you can queue elements based on specific requirements, and then we can implement PriorityQueue for customisation. With Priority Queue, it depends on the priority heap either naturally or via the comparator on their relative priority.   Features of priority queues in java include- Juggle multiple programs and their execution Important to networking systems Typically implemented using the heap data structure. 110. When is it ideal to use and compare the Runnable interface in Java? When we need to extend a class with some other classes and not the threads then runnable interfaces are an ideal choice.  111. What is the difference between start() and run() method of thread class? The start() method adds and creates a new thread. And code in run() method gets executed in the new thread only. While run() method will execute code in the current thread only. 112. What is Multithreading? In Java, we can execute multiple threads simultaneously, which is known as Multithreading. It helps the program to multitask while taking less memory and giving higher performance. In Multithreading, threads are lightweight, share the same space, and are quite affordable in every aspect.  Features of multi threading in java- Allows to create lightweight process Multiple threads can be executed can be created in the program. Saves time as it helps in running multiple operations. The threads are independent, so it does not block other operations. 113. Explain the difference between process and threads. Here the main differences are: A Java program in execution is termed as a process while a thread represents a subset of the process only.  Processes represent different spaces in the memory, while threads have the same address. Processes are entirely independent, while threads are part of the process only. Slow communication between inter-processes, while the inter-thread communication is swift.  Refer to the below-mentioned table to understand the difference- Process Threads Allocate new resources each time a program is run. Share resources of process. Generally slower than thread. Generally faster process. Communicate through IPC. Communicate freely. Have a separate address space. Share address space. 114. Explain the meaning of inter-thread communication. Inter-thread communication is defined as the process that allows communication between multiple synchronised threads. Its main aim is to avoid thread pooling in Java. Communication is achieved through the methods of wait(), notify(), and notifyAll().    115. Explain the wait() method. With wait() method, you can allow the thread to be in the waiting stage while the other thread is locked on the object. Thus, the wait() method can add significant waiting duration for threads.  Here is a syntax to represent this: 1 2 3 4 5 6 public static void main (String[] args){ Thread t = new Thread (); t.start (); Synchronized (t) { Wait(); } 116. What is the main difference between the notify() and notifyAll() method in Java? notify() method sends a signal to wake up only a particular thread in the waiting pool whereas notifyAll() wakes up all the threads in the waiting stage of the pool.  117. Define the main differences between sleep() and wait(). Sleep() pauses or stops the current thread progress by suspending execution for a particular duration while not releasing the lock. While wait() causes a waiting duration for a thread after invoking a notify() method for waking later.  Refer to the below-mentioned table between sleep() and wait(). sleep() wait() Static method Non-static method Doesn’t release lock Releases the lock Used to introduce a pause on execution Used for inter-thread communication 118. Explain the join() method in relation to the thread in Java.  The join() method allows combining one thread with one of the continuous threads. Here is a syntax for join() method: 1 2 3 4 5 public static void main (String[] args){ Thread t = new Thread (); t.start (); t.join (); } 119. Explain the Yield method of Thread. Yield method is a static method and does not release any lock in the threads. Here, a Yield() method empowers the current thread to a more runnable thread while allowing the other threads for keeping the execution. Thus, equal thread priority threads can run regularly.  120. What is the Starvation stage? Starvation is a phase when a thread fails to gain access to shared resources and is not able to make any progress.  It is when the thread is not able to gain regular access to the shared resources. When shared resources are made unavailable for long periods. 121. What is Deadlock for a thread? Deadlock defines a stage when two or multiple threads get blocked forever in wait for each other.  122. Define Serialisation and Deserialisation in Java? Serialisation is the process for transforming the state of an object into a particular byte stream ideally suited for JPA, JMS, RMI, JPA, and Hibernate technologies. While the opposite process of changing a byte stream into an object is called deserialisation. Both processes are platform-independent, so they allow you to serialise in one platform and deserialise into an entirely different platform efficiently.  123. What is the importance of transient variables? The importance of transient variables lies in the deserialisation that is set to the default variables and not used with the static variables. 124. What are volatile variables? Volatile variables play a crucial role in the synchronisation and reading from the main memory while avoiding the thread cache memory.  125. What is SerialVersionUID? In the Serialised process, an object is stamped with a specific version ID number for the respective object class. This number is termed as SerialVersionUID and plays a crucial role in verifying during the deserialisation process for checking the compatibility on sender and receiver, respectively.  126. What is the process for cloning an object in Java? With Object cloning, you can create an exact copy of the original object. For cloning to be possible, a class must have the support for cloning with the java.lang.Cloneable interface and allow override clone() method from the original object class.  Here a simple syntax for the clone() method: protected Object clone() throws CloneNotSupportedException  In case the clone does not implement it then it generally throws an exception with the ‘CloneNotSupportedException’. 127. Define the class that remains superclass for each class? Object class. 128. Define whether a string class is mutable or immutable? String class represents an immutable state. So once an object is created, this cannot change any further.  129. How do you differentiate between StringBuffer and StringBuilder class? StringBuilder is quicker than the StringBuffer.  StringBuffer is synchronised while StringBuilder is not synchronised.  StringBuffer offers a thread-safe environment, while StringBuilder has no thread-safe capability.  130. What is the use of the toString() method in Java? In Java, toString() retrieves or returns the string representation from any object.  131. What is a garbage collection in Java? As objects get dynamically allocated via the operator, Java system also handles the deallocation of the memory used automatically in case there are no references for the object that remains for a significant duration. This process of keeping the system free of objects that don’t have use is known as Garbage Collection in Java. The main aim of the garbage collection is to make it more memory efficient management.  132. What is the number of times a garbage collector calls finalize() method for a specific object? You can call the finalize() method in garbage collection only once.  133. Define the ways to call the garbage collection. There are two ways to call the garbage collection: System.gc() Runtime.getRuntime().gc() 134. Can we force Garbage Collection? No, this is an automatic process. You can call the garbage collection method but can’t force it. Still, it does not guarantee that it would be complete.  135. What are the different data types in Java? Explain. Here is a shortlist to help you with data types: byte – 8 bit short – 16 bit char – 16 bit Unicode int – 32 bit (whole number) float – 32 bit (real number) long – 64 bit (Single precision) double – 64 bit (double precision) 136. Define the Unicode. Unicodes are a way to define international characters in human languages, and Java uses this Unicode structure to symbolise the characters. 137. Define literal. A literal is a constant value assigned to a particular variable   // Here 105 is a literal int num = 105 138. Define the type of casting in Java? In the case of assigning a value of one data type to another data type, these two may or may not be compatible and require conversion. Java will automatically convert in case of compatible data types. While if the data types are not compatible, then these must be cast for successful conversion. Casting has two basic types: Implicit and Explicit.   139. Explain the two different types of typecasting? Implicit: Defines the storing of values from smaller data types into larger data types, performed by the compiler only.  Explicit: Defines the storing of values from larger data types into smaller data types that may result in information loss. 140. Why is Java considered platform-independent? Java is considered platform-independent due to its use of the Java Virtual Machine (JVM), which allows Java programs to run on any operating system without modification. When a Java program is compiled, it is converted into bytecode, which is a standardized, platform-neutral format. This bytecode is then executed by the JVM, which interprets it for the specific operating system on which it is running. This unique architecture enables the Java philosophy of “write once, run anywhere,” allowing developers to write applications that can be deployed across different systems without needing to be recompiled for each one. Conclusion The above Java interview questions will provide a good start for preparing for the interview. Practice your coding skills, too, though, and make sure to be thorough in these questions and their related concepts so that when the interviewer fires a Q, you are ready to win the round with your A. Oh, and don’t forget 3 (inconspicuous) breaths when you present yourself before the interviewer. If you’re interested to learn more about Java, full-stack software development, check out upGrad & IIIT-B’s Executive PG Programme in Software Development – Specialisation in Full Stack Development which is designed for working professionals and offers 500+ hours of rigorous training, 9+ projects, and assignments, IIIT-B Alumni status, practical hands-on capstone projects & job assistance with top firms. All the best! Hope you Crack your Interviews !!

by Arjun Mathur

13 May 2024

Blogs

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Spring has become one of the most used Java frameworks for the development of web-applications. All the new Java applications are by default using Spring core and Spring MVC frameworks. Thanks to its growing popularity, recruiters all over the globe are looking for candidates hands-on with the Spring framework. If you’re appearing for an interview for a Java developer role, Spring MVC is one of the first things that you should brush up your knowledge on Spring framework interview questions – irrespective of whether you’re a fresher or someone with experience. Also, check out our free courses to get an edge over the competition. After all, the Spring MVC framework is the most commonly used Java frameworks, and you are bound to get asked questions in and around the same, in any Java (or any related interview) interview you sit for. If you didn’t know, Spring MVC is a robust Java-based framework that helps build web applications. As the name suggests, it uses an MVC architecture – Model, View, Controller. Spring MVC provides an elegant way of using Spring with the MVC framework. Released in 2002, the Spring framework’s is an open-sourced framework, that means developers all around the world can contribute to the development and further releases of the framework. Check out Advanced Certification in DevOps Learn to build applications like Swiggy, Quora, IMDB and more Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript That also means that there is an ever-active community of developers out there to help you with your queries. Being open-sourced also adds to the plethora of benefits that the Spring framework offers. Especially if you’re beginning with your career in Java, you’d require guidance, and the diverse community of Java developers ensures you don’t lack any guidance when it comes to working with Spring MVC. Check Out Advanced Certification in Cloud Computing It is important to understand the flow of Spring MVC to gain an in-depth knowledge of Java.  With so many benefits to offer, there shouldn’t be an iota of doubt as to why Spring MVC is an interview’s favorite topic to question you on. In this article, we’ll be talking about 15 such Spring MVC must-know questions which you can expect to encounter in any interview you sit for. Let’s learn about the interview questions on Spring MVC for freshers and other Spring MVC interview questions and answers for experienced candidates, which will help you ace your interview.  1. What is the Spring framework? To start off our list of interview questions on Spring MVC, let us start with the basics of what Spring MVC stands for.  Spring is an open-source framework that was built to simplify application development. It has a layered structure which allows the developer to be selective about the components they use. It has three main components – Spring Core, Spring AOP, and Spring MVC. Further, you can talk about your experience with Spring, if any. That’ll add a lot of weight to your answer. Why Companies are Looking to Hire Full Stack Developers 2. What are the main features of Spring framework? Spring framework offers a lot of features to make the developer’s life easy. Some of them are: Lightweight: Spring is extremely lightweight, the basic version is around 1MB, with negligible processing overheads. Inversion of Control (IoC): Dependency Injection or Inversion of Control is one of the most important features of Spring. Using IoC, the developers don’t need to create a complete environment for the object and its dependencies; they can simply create and test the object they are handling at the given point in time. Object dependencies will be included or called upon when the need arises. It majorly creates a window in the case of configuration management. The container, therefore, consists of different assembler codes that solely exist for configuration management.   Aspect-Oriented Programming: Spring supports Aspect-Oriented Programming. AOP isolates secondary functions from the programmer’s business logic. This not only provides modularity but also makes the code maintainable. MVC architecture: Spring comes with an MVC framework for web-applications. This framework is highly configurable using various technologies like JSP, Tiles, iText, and POI. JDBC exception handling: Spring comes with a predefined JDBC abstraction layer which simplifies the overall exception handling process. Spring MVC network is also the basis of power for other Spring-based projects like Spring Boot, Spring Cloud, and SpringGraph QL.  Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses upGrad’s Exclusive Software and Tech Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4   3. Explain a bit more about Dependency Injection. Spring MVC questions like these check your test your clarity on basic concepts. Dependency injection is the fundamental aspect of Spring frameworks which theoretically injects objects with dependencies that helps in responsibly managing the components that already exist in the container. Inversion of Control or Dependency Injection aims to simplify the process of object creation by following a simple concept – don’t create objects, just describe how they should be created. Using IoC, the objects are given their dependencies at build-time by an external entity that is responsible for coordinating each object in the system. In essence, we’re injecting dependencies into objects using IOC or Dependency Injection. For example, if class One needs to operate an object which is possessed by class Two, which instantiates or operates a particular method, then it can be concluded that in this case, class One depends on Class Two.  This particular example, however, is only possible theoretically and not in the real world because it can lead to several problems in the module, like system failure and other important issues. This can also lead to loose coupling, which can be possible because of two classes being intertwined for common functionality.  Make sure you offer such clarity in your Spring MVC questions. This also marks one of the most important Spring MVC interview questions for experienced candidates.  4. Explain the different types of Dependency Injections in Spring? When to use which? Spring provides the developers with the following two types of dependency injections: Constructor-based DI: Constructor-based DI is accomplished by passing a number of arguments (each of which represents a dependency on other class) to a class’s constructor. Simply, dependencies are given in the form of constructor parameters. CDI is declared as the <constructor-arg> tag in the configuration bean file in this particular parameter.  Setter-based DI: When you are working with a no-argument constructor, you will set values by passing arguments through setter function to instantiate the bean under consideration, this is called setter-based dependency injection. For example, a class GFG can use Setter Dependency Injection (SDI) to set the property tag in the bean- configuration file.  When will you use which one of these, boils down to your requirements. However, it is recommended to use Setter-based DI for optional dependencies and Constructor-based DI for mandatory dependencies. Interview with Farooq Adam, Co-Founder, Fynd 5. What is the Spring MVC framework? Spring MVC is one of the core components of the Spring framework. It comes with ready to use components and elements that help developers build flexible and robust web applications. As the name suggests, the MVC architecture separates the different aspects of the application – input logic, business logic, and UI logic. It also provides a loose coupling between the M, V, and C of the application. These are classified further into:  Model (M): This contains the application data with a single object and a collection of objects.  View (V): A view requires provided information in a specific format. Generally, in this case, JSP+ JSTL uses this way to create a view page. This consists of components of various technologies like Apache Velocity, Thymeleaf, and FreeMarker.  Controller ( C): This contains the business logic of an application. The annotation of the @controller is used as a mark to class the controller in the program.  This question is a fine example of Spring MVC interview questions for experienced.  In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses 6. What are some benefits of Spring MVC framework over other MVC frameworks? The Spring MVC framework has some clear benefits over other frameworks. Some of the benefits are: Clear separation of roles –  There is a specialised object for every role, thus providing a clear separation of roles. Reusable business code – With Spring MVC, you don’t need to duplicate your code. You can use your existing objects as commands instead of mirroring them in order to extend a particular framework base class. Customizable binding and validation- This helps in rewriting the code from scratch and also taking up the previous codes at times for a proper binding and validation following the function. It is very feasible and one of a kind.  Customizable locale and theme resolution- One of the important components of Spring MVC is the customizable theme resolution. The developer can surely change these based on the needs provided by the organization or the required programming clientele.  Customizable locale and theme resolution Customizable handler mapping and view resolution From Spring 2.0 onwards, the framework comes with a JSP form tag library which makes writing forms in JSP pages much easier. 7. What is DispatcherServlet? Spring MVC framework is request-driven and is designed around a central Servlet that handles all the HTTP requests and responses. The DispatcherServlet, however, does a lot more than just that. It seamlessly integrates with the IoC container and allows you to use each feature of Spring. On receiving an HTTP request, the DispatcherServlet consults HandlerMapping (these are the configuration files) to call the appropriate Controller. Then, the controller calls appropriate service methods to set the Model data. It also returns the view name to DispatcherServlet. DispatcherServlet, with the help of ViewResolver, picks up the defined view for the request. Once the view is finalized, the DispatcherServlet passes the Model data to View – where it is finally rendered on the browser. What is Test-driven Development: A Newbie’s Guide 8. What is the front controller class of the Spring MVC? A front controller is a controller which handles all requests for a Web application. When it comes to Spring MVC, DispatcherServlet is that front controller. When a web request is sent to a Spring MVC application, the DIspatcherServlet takes care of everything. First, it takes the request. Then, it organizes the different components like request handlers, controllers, view resolvers, and such – all needed to handle the request. And finally, it renders the content on the browser. 9. What is a Viewresolver pattern and how does it work in MVC? View Resolver is a J2EE pattern which allows the applications to dynamically choose technology for rendering the data on the browser (View). Any technology like HTML, JSP, Tapestry, XSLT, JSF, or any other such technology can be used for View. The View Resolver pattern holds the mapping of different views. The Controller returns the name of the View which is then passed to View Resolver for selecting the appropriate technology. 10. How does Spring MVC provide validation support? Spring primarily supports two types of validations: Using JSR-303 Annotations and any reference implementation, for example, Hibernate Validator, or Implementing org.springframework.validation.Validator interface. 11. A user gets a validation error in other fields on checking a checkbox, after which, he unchecks it. What would be the current selection status in command object of the Spring MVC? How will you fix this issue? This is one of the trickier questions to answer if you aren’t aware of the HTTP Post behaviour in Spring MVC. During HTTP Post, if you uncheck the checkbox, then HTTP does not include a request parameter for the checkbox – which means the updated selection won’t be picked up. To fix that, you can use hidden form field which starts with ‘_’. This is one of the toughest Spring MVC interview questions.  How to Succeed in Your First Software Development Job 12. How will you compare the MVC framework to the three-tier architecture? A Three-tier architecture is an architecture style whereas MVC is a design pattern. Having said that, in larger applications, MVC forms the presentation tier of a three-tier architecture. The Model, View, and Controller are concerned only with the presentation – they use the middle tier to populate their models. 13. How should we use JDBC in Spring to optimize the performance? Spring provides a template class called as JDBCTemplate. Using JDBC with this template gives manifolds better performance. This, therefore, helps in providing accurate results and finally makes programming easier for the developer.  14. What do you mean by a “Bean” in the context of Spring framework? Any class that is initialized by the IoC container is known as a bean in Spring. The lifecycle of a Spring Bean is managed by Spring IoC Container. Bean helps provide accuracy in the overall Spring MVC framework giving optimal results.  Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? 15. What is a “Scope” in reference to Spring Beans? Spring Beans comes with following five scopes: Prototype: Whenever there’s a request for a bean, a separate prototype is created each time. Request: It is like the previous scope, but only for web-based applications. For each HTTP request, Spring creates a new bean instance. Singleton: There’s only one bean created for every container, and it acts as the default scope of that bean. In all these instances, the beans cannot use a shared instance variable as it can lead to data-inconsistency. Session: A bean is created for every HTTP session Global-session: Global session is created for Portlet applications. The Spring framework is extendable, that is, you can create your own scope as well. The “scope” attribute of the bean element is used to define the scope. How to Become a Full Stack Developer 16. What are the different types of AutoWire?  This is one of the most common Spring MVC interview questions. Spring’s autowiring feature allows the framework to automatically inject dependencies into Spring beans. Spring supports a variety of auto-wiring modes: No auto-wiring (by default): In this mode, auto-wiring is disabled, and dependencies must be explicitly defined using the components in the bean configuration. Autowiring by Type (autowire=”byType”): Spring wires a property if its type is the same as one of the beans declared in the container. If there is more than one matched bean, an error is returned. Autowiring by Name (autowire=”byName”): In this mode, Spring searches for a bean that shares the same name as the property being authored. If the dependence is discovered, it is injected; otherwise, an error is returned. Autowiring by Constructor (autowire=”constructor”): Spring matches and injects dependencies depending on the constructor arguments. This style is very handy for working with several constructors or intricate dependents. Autowiring by Qualifier (@Qualifier annotation): When combined with @Autowired, @Qualifier allows you to define the precise bean name that will be injected when the container contains numerous beans of the same type. 17. What are Spring Interceptors?  This is a commonly asked Spring MVC interview questions for experienced. Spring interceptors are components that enable developers to pre-handle, post-handle, or alter requests and answers within a Spring MVC application. They allow you to inject custom behaviour into the request processing lifecycle. Interceptors are very useful for cross-cutting issues like logging, security, authentication, and altering the model before it reaches the view. To answer this Spring MVC interview questions, talk about ways to use interceptors in a Spring MVC application and how they must be specified in the application context or through Java configuration.  Spring interceptors are an effective tool for expanding the functionality of a Spring MVC application in a modular and reusable manner. They contribute to cleaner code by isolating concerns and encouraging the reuse of certain portions of request processing logic across different areas of the application. In a Spring MVC application, interceptors are created by implementing the HandlerInterceptor interface. This interface contains three methods: preHandle(): Called before the actual handler function is run. It may be used for a variety of functions, including request pre-processing, authentication checks, and logging. postHandle(): Runs after the handler procedure but before the view is rendered. This function allows developers to conduct actions on the model or alter the ModelAndView. afterCompletion(): Called after the entire request has been processed, including displaying the view. It is useful for operations like cleaning and resource release. 18. What is a Spring Configuration File?  This is one of the most anticipated Spring MVC interview questions for 10 year experience.  The Spring Configuration File is an XML or Java-based configuration file that is used to create and configure Spring beans. These configuration files are critical to the Inversion of Control (IoC) container, which governs the Spring beans’ lifespan. There are two major types of Spring configuration files: XML-based Configuration: Beans and their dependencies are defined by developers using XML markup in this configuration style. The configuration file normally contains a <beans> element as the root, followed by individual <bean> elements that specify the beans, their attributes, dependencies, and other configurations. Java-based Configuration: With the introduction of Java configuration in Spring, developers may now create beans and their connections using simple Java classes annotated with @Configuration. These classes frequently use @Bean annotations to define individual beans, as well as other annotations such as @ComponentScan or @Import to describe scanning packages or import other configuration classes. 19. When is Autowiring used?  This is also one of the most crucial interview questions on Spring MVC. To answer Spring MVC framework interview questions like this, start by mentioning that autowiring may not be appropriate for all scenarios.  Developers should think carefully about the ramifications of autowiring, such as the possibility of ambiguity when numerous candidates exist. Furthermore, it is critical to understand the many autowiring options available in Spring (byType, byName, constructor, etc.) and select the one that best meets the application’s needs. Reducing Configuration Boilerplate: Autowiring reduces the amount of boilerplate code necessary to configure dependencies. Rather than manually describing each dependency in the configuration file, Spring may identify and inject them based on predefined criteria. Maintaining Loose Coupling: Autowiring facilitates loose coupling among components. By relying on the container to automatically wire dependencies, components are not directly aware of one another, making the system more modular and maintainable. Simplifying Dependency Injection: Autowiring can make it easier to configure a bean with several dependencies. Developers do not need to explicitly wire each dependency; Spring resolves and injects them based on the autowiring option selected. Easier Maintenance and Refactoring: Autowiring simplifies code maintenance and refactoring. When new dependencies are introduced or old ones are adjusted, the configuration file does not need to be explicitly updated; Spring can react to changes automatically. Promoting Convention Over Configuration: Autowiring is consistent with the Spring idea of “convention over configuration.” It encourages developers to utilise naming conventions or particular annotations, which allow Spring to infer dependencies and wire them appropriately. 20. What is a Spring IoC Container?  The Spring IoC (Inversion of Control) Container is a core component of the Spring Framework that manages the lifespan of Java objects, generally known as beans. Traditional Java programmes frequently delegate responsibilities for creating and managing objects (beans) to the application code. However, the Spring IoC Container reverses this control by taking over the task of producing and maintaining beans. The Spring IoC Container, has the following key properties and functionalities: Bean Definition: Bean definitions are metadata that explains how to construct and configure a bean. They are the foundation of the IoC Container. These bean definitions can be defined in XML files, Java configuration classes, or a combination of the two. Bean Lifespan Management: The container handles the whole lifespan of beans, including instantiation, dependency injection, initialization, and destruction. This enables developers to concentrate on building business logic while the container tackles infrastructural issues. Dependency Injection (DI): The IoC Container supports Dependency Injection, which is a crucial Spring Framework concept. Dependencies between beans are injected at runtime, eliminating tight coupling and improving application modularity and maintainability. Inversion of Control: Unlike traditional programming, the control flow in Internet of Things applications is inverted. Instead of the application code directing the execution flow, the IoC Container manages bean creation and wiring. Configuration Options: The IoC Container enables developers to configure beans via XML-based configuration files, Java-based configuration classes, or a mix of the two. This flexibility allows developers to select the configuration approach that best meets their needs and preferences. This also falls under one ofthe top-asked interview questions on Spring MVC. Hence, it is important to prepare Spring MVC framework interview questions when you’re preparing solo or even preparing a one-on-one mock interview with your friend.  21. What are the advantages and disadvantages of the Spring MVC framework?  This is one of the popularly asked Java MVC interview questions. Additionally, knowing the advantages and disadvantages of the Spring Framework is extremely important while simultaneously preparing for Spring MVC interview questions for 5 years experience, as well as Spring boot MVC interview questions.  Advantages  Modular and Flexible: The design of Spring MVC is modular and flexible, enabling programmers to arrange their code in a logical and manageable way. It encourages the separation of issues, making it easier to handle various areas of the app. Loose Coupling: The framework promotes loose coupling between components, making it easier to replace or alter individual modules without impacting the overall system. This improves maintainability and encourages proper software design practices. Integration with Other Spring Technologies: Spring MVC works smoothly with other Spring Framework components including the Spring IoC container, Spring AOP (Aspect-Oriented Programming), and Spring Security. This allows for the creation of extensive and well-structured applications. Disadvantages Learning Curve: Spring MVC has a learning curve, particularly for developers new to the Spring Framework. Understanding concepts like inversion of control, dependency injection, and the MVC architecture might take time. Configuration Complexity: While Spring MVC provides configuration flexibility, some developers, particularly those working on bigger projects, may find XML-based configuration files or Java configuration classes to be complicated. This complexity can be reduced by good documentation and training. Annotation Overhead: While annotations can make code more succinct, using too many annotations might result in code that is difficult to read and comprehend. It is critical to find a balance between utilising annotations for convenience and ensuring code readability.  Wrapping Up This was all about the must-know Spring interview questions and answers revolving around the Spring framework – and Spring MVC, to be precise. If you’re a Java developer looking to get started with Spring, there couldn’t be a better time! Read more if you are looking for Java interview questions. Spend some of your precious time to get your hands on Java Spring interview questions and you will be good to go. Organizations are on a look-out for developers having strong command on this framework – thanks to the features it has to offer. The above questions have provided you with great insights about interview questions for Spring MVC freshers, Spring MVC interview questions and answers for experienced alike, accompanied with other scrutinizing details for this particular subject matter.  Enroll in Software Engineering Courses from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career.

by Arjun Mathur

04 Mar 2024

Blogs

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Java is a versatile language that supports object-oriented programming and code reusability with building relationships between two classes. There are two types of relationships or associations in Java used to reuse a code and reduce duplicity from one class to another. These relationships are IS-A(Inheritance) and HAS-A (Association). While there is a tight coupling between the IS-A classes, HAS-A classes are loosely coupled and more preferable for the programmers. The HAS-A relationship is divided into two types, viz., aggregation and composition in Java. This article is based on the OOP concept of composition. We will see many real-life examples of how the composition is coded and the advantages gained when implemented. Check out our free courses related to software development. Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript A Brief Narration of Associations or Relationships in Java In object-oriented programming, objects are related to each other and use the common functionality between them. This is where the topics of Inheritance, Association, Aggregation, and Composition in Java programs come.  Inheritance (IS-A) and Association (HAS-A) in Java Check Out upGrad’s Java Bootcamp 1. Inheritance (IS-A) An IS-A relationship signifies that one object is a type of another. It is implemented using ‘extends’ and ‘implements’ keywords. Example: HP IS-A laptop Our learners also read: Learn java online free! 2. Association (HAS-A) A HAS-A relationship signifies that a class has a relationship with another class. For instance, Class A holds Class B’s reference and can access all properties of class B. Example: Human body HAS-A Heart Source   Source 3. Aggregation Vs Composition Has-A relationship or Association can be divided into aggregation and composition. An aggregation container class and referenced class can have an independent existence. A composition reference class cannot exist if the container class is destroyed. Check Out upGrad’s Advanced Certification in Blockchain   Let’s take an example to understand aggregation and composition. A car has its parts e.g., engines, wheels, music player, etc. The car cannot function without an engine and wheels but can function without a music player. Here the engine and car have a composition relation, and the car and music player have an aggregation relationship. In the case of Aggregation, an object can exist without being part of the main object. Aspect Aggregation Composition Definition Aggregation represents a “has-a” relationship where one class contains a reference to another class. It’s like saying a car has wheels. Composition is a stricter form of aggregation where one class owns another class, meaning the contained class’s existence is dependent on the container. It’s like saying a car has an engine. Dependency In aggregation, the contained class can exist independently of the container class. If the container is destroyed, the contained class can still exist. In composition, the contained class’s lifecycle is tied to the container. If the container is destroyed, the contained class is also destroyed. Flexibility Aggregation is more flexible as it allows the contained class to be shared among multiple containers. Composition is less flexible because the contained class is exclusive to its container and cannot be shared. Relationship Aggregation signifies a weaker relationship between classes. The contained class can belong to multiple containers simultaneously. Composition signifies a stronger relationship where the contained class is part of the container and cannot be associated with any other container. Examples An example of aggregation is a university having departments. Departments can exist independently of the university and can belong to multiple universities. An example of composition is a car having an engine. The engine is an integral part of the car and cannot exist without it. Composition Vs. Inheritance   Aspect Composition Inheritance Definition Composition involves creating complex objects by combining simpler ones, composition in oops Inheritance is a mechanism where a new class is derived from an existing class. Relationship The relationship between objects is “has-a.” The relationship between objects is “is-a.” Flexibility Offers more flexibility as it allows changing the parts of the object independently. Less flexible because changes to the base class can affect all derived classes. Code Reusability Promotes code reuse by allowing the use of existing classes without being tied to their implementation details. Code reuse is facilitated through the extension of existing classes. Complexity Typically leads to simpler, more modular code. Can lead to complex class hierarchies, which might be harder to understand. Dependency Objects can exist independently of each other. Dependent on the base class, changes to which can affect derived classes. Encapsulation Encourages encapsulation as objects hide their internal details. May violate encapsulation as derived classes have access to all members of the base class.   Source Composition in Java A composition in Java between two objects associated with each other exists when there is a strong relationship between one class and another. Other classes cannot exist without the owner or parent class. For example, A ‘Human’ class is a composition of Heart and lungs. When the human object dies, nobody parts exist. The composition is a restricted form of Aggregation. In Composition, one class includes another class and is dependent on it so that it cannot functionally exist without another class. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses upGrad’s Exclusive Software and Tech Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4   Implementation of Composition in Java The engine and car relationship are implemented using Java classes as below. In Java, the ‘final’ keyword is used to represent Composition. This is because the ‘Owner’ object expects a part object to be available and function by making it ‘final’. public class Car {            private final Engine engine;      public Car(){     engine  = new Engine(); } }  class Engine { private String type; } Let us take another example that depicts both inheritance and composition. Source  In this program, the class Honda is a Car and extends from the class Car. The car engine Object is used in the Honda class. class CarEngine {     public void StartEngine(){         System.out.println(“The car engine has Started.”);     }     public void stopEngine(){         System.out.println(“The car engine has Stopped.”);     } }  class Car {     private String colour;     private int maxi_Speed;     public void carDetails(){         System.out.println(“Car Colour= “+colour + “; Maximum Speed= ” + maxi_Speed);     }     //Setting colour of the car     public void setColour(String colour) {         this.colour = colour;     }     //Setting maximum car Speed     public void setMaxiSpeed(int maxi_Speed) {         this.maxi_Speed = maxi_Speed;     } }  class Honda extends Car{     public void HondaStart(){         CarEngine Honda_Engine = new CarEngine(); //composition         Honda_Engine.startEngine();         } }  public class Main {     public static void main(String[] args) {            Honda HondaJazz = new Honda();         HondaJazz.setColour(“Black”);         HondaJazz.setMaxSpeed(160);         HondaJazz.carDetails();         HondaJazz.HondaStart();     } } Output: Car Colour = Black; Maximum Speed = 160 The car engine has started.  The output is derived using composition and shows the details of the Honda Jazz car. Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses UML Denotations of Association The relationships of association, aggregation, and composition in Java between classes A and B are represented as follows in UML diagrams: Association: A—->B Composition: A—–<filled>B Aggregation: A—–<>B Get Software Engineering degrees online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career. Learn Java Tutorials Java Tutorials Java Classes and Objects Java 8 features Operators in Java Static Keyword In Java Switch Case In Java Packages in Java For Loop in Java Thread Lifecycle In Java OOP vs Functional vs Procedural Instance variables in Java Loops in Java Identifiers in Java Java Frameworks String Comparison in Java charAt() in Java View All Java Tutorials Benefits of Composition in Java Using composition design technique in Java offers the following benefits: It is always feasible to “prefer object composition over class inheritance”. Classes achieve polymorphism and code reuse by composition. The composition is flexible, where you can change class implementation at run-time by changing the included object, and change its behaviour. A composition-based design has a lesser number of classes. THE “HAS-A” relationship between classes is semantically correct than the “IS-A” relationship. Composition in Java offers better class testability that is especially useful in test-driven development. It is possible to achieve “multiple inheritances” in languages by composing multiple objects into one. In composition, there is no conflict between methods or property names. Check out all trending Java Tutorials in 2024.  Features of Composition in Java Composition is a fundamental concept in Java programming that enables the creation of complex objects by combining simpler ones along with description, what is composition in java with example.  It facilitates code reuse, maintainability, and flexibility in designing software applications. Let’s explore the key features of composition in Java: Object Composition Object composition involves creating complex objects by combining simpler ones. In Java, this is achieved by defining classes that contain references to other classes as instance variables. This allows objects to be composed of other objects, forming a hierarchical structure. Has-a Relationship Composition establishes a “has-a” relationship between classes, where one class contains objects of another class. This relationship signifies that a class has references to other classes to fulfill its functionality. For example, a Car class may have instances of Engine, Wheels, and Seats classes and understanding what is composition in java. Code Reusability Composition promotes code reusability by allowing the reuse of existing classes within new classes. Instead of inheriting behavior through inheritance, classes can reuse functionality by containing instances of other classes. This enhances modularity and reduces code duplication, composition example in java. Encapsulation Encapsulation is maintained through composition as the internal details of the composed objects are hidden from the outside world. Each class manages its own state and behavior, providing a clear separation of concerns. This enhances code maintainability and reduces the risk of unintended side effects and composition writing examples. Flexibility and Modifiability Composition offers greater flexibility compared to inheritance, as it allows classes to change behavior dynamically by replacing or modifying the objects they contain. This promotes a modular design approach, where individual components can be modified or extended without affecting the entire system. Dynamic Behavior With composition, the behavior of an object can be dynamically changed at runtime by replacing its constituent objects. This dynamic composition enables the creation of highly adaptable and customizable systems, where different configurations of objects can be used to achieve varying functionality, with an understanding of aggregation and composition in java. Loose Coupling Composition helps in achieving loose coupling between classes, as objects are accessed through interfaces rather than concrete implementations. This reduces dependencies between classes and promotes better code maintainability and testability. Granular Control With composition, developers have granular control over the behavior and state of objects. They can selectively expose certain functionalities of composed objects while encapsulating others, providing a clear interface for interaction with the object, like composition in java. Benefits of Composition in Java Encapsulation and Modularity Composition promotes encapsulation, which is the practice of bundling data and methods that operate on that data within a single unit, with an understanding of object composition in java. By encapsulating related functionalities into separate classes, you can create modular and reusable components. This modularity enhances code organization and makes it easier to understand, maintain, and extend, with examples of composition. Code Reusability One of the primary benefits of composition is code reusability. Instead of inheriting behaviors from a single parent class, you can compose objects by combining multiple classes to achieve the desired functionality. This approach allows you to reuse existing classes in different contexts, reducing code duplication and promoting a more efficient development process. Flexibility and Loose Coupling Composition promotes loose coupling between classes, which means that the components of a system are independent and can be modified or replaced without affecting other parts of the codebase. This flexibility is essential for building scalable and maintainable applications, as it enables developers to make changes to one part of the system without impacting the entire application. Better Control over Behavior With composition, you have finer control over the behavior of your objects compared to inheritance. Instead of inheriting all the characteristics of a parent class, you can selectively choose which functionalities to include in a class by composing it with the appropriate components. This granularity allows you to design classes that are tailored to specific requirements, leading to cleaner and more efficient code. Avoiding the Diamond Problem Inheritance can result in the “diamond problem,” where ambiguity rises when a class inherits from any two or more classes that have an ancestor. Composition helps avoid this issue by allowing you to combine functionalities from multiple classes without creating complex inheritance hierarchies. This simplifies the design and prevents potential conflicts that may arise from multiple inheritance. Facilitates Testing and Debugging Composition facilitates unit testing and debugging by enabling you to isolate and test individual components independently. Since each class encapsulates a specific set of functionalities, you can easily mock dependencies and simulate different scenarios during testing. Additionally, debugging becomes more manageable as the codebase is divided into smaller, more focused units. When to Use Composition in Java? In Java programming, composition is a powerful concept used to build complex objects by combining simpler ones. It involves creating objects by incorporating other objects within them. Knowing when to utilize composition is essential for writing clean, maintainable, and efficient code, with various composition writing sample. Understanding Composition Composition establishes a “has-a” relationship between classes, where one class contains another as a part of its state. This is different from inheritance, which establishes an “is-a” relationship. In composition, the contained object does not inherit behavior from the containing class but rather is used to provide functionality or data, with english composition examples. Encapsulation and Code Reusability One of the primary use cases for composition is encapsulating functionality. By breaking down complex systems into smaller, more manageable components, you can encapsulate related functionality within separate classes. This promotes code reusability and modular design, making your codebase easier to understand and maintain. Flexibility and Modifiability Composition allows for greater flexibility in software design. Since objects are composed of other objects, you can easily modify or replace components without affecting the entire system. This modular approach simplifies testing and debugging and enables you to adapt your code to changing requirements more efficiently when association aggregation and composition in java. Preventing Tight Coupling Using composition helps avoid tight coupling between classes, which can make code brittle and difficult to maintain. By relying on interfaces or abstract classes, you can decouple components, making them interchangeable and reducing dependency on specific implementations. This enhances the scalability and extensibility of your codebase. Promoting Single Responsibility Principle Composition encourages adhering to the Single Responsibility Principle (SRP), which states that a class should have only one reason to change. By breaking down functionality into smaller, focused classes, each responsible for a specific task, you can create more cohesive and understandable code. This improves code maintainability and reduces the risk of introducing bugs when making modifications. Example: GUI Components Consider a graphical user interface (GUI) framework where various components such as buttons, text fields, and panels are composed to create complex interfaces. Each component encapsulates its behavior and appearance, allowing developers to mix and match them to design diverse user interfaces efficiently. Conclusion Composition in Java offers many advantages while programming and is one of the favoured design methods. In this article, we have tried to make you understand this important concept with real-life examples and practical code. Composition offers flexibility and robust code. Its code reusability feature helps in avoiding code duplication and achieving cost-effectiveness. This makes it one of the widely used methods in various programs.  Learn composition in Java with upGrad’s Master of Science in a Computer Science course which is aimed to make you learn and upgrade your skills in software development. Eligibility A Bachelor’s Degree with 50% or equivalent marks. No initial coding experience is needed. Pricing The program fee starts at Rs.13, 095/month for Indian Residents and USD 5999 for International residents.

by Arjun Mathur

19 Feb 2024