String to Array in PHP: A List of Popular Functions for 2025

Converting a string to array in PHP is a crucial operation for many programming tasks, especially when dealing with large datasets or parsing text. In real-world scenarios, such as processing CSV files or user input, this functionality is essential. 

For instance, converting a comma-separated string of items into an array allows easy manipulation of individual elements, like sorting a list of products or processing form data. Understanding how to do this efficiently is key to optimizing PHP applications.

In this article, we will look at some of the important functions of converting a string to array in PHP. We will look at each PHP function and see how it is written in the program.

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Converting String to Array in PHP: A List of Popular Functions

In many cases, an array is preferable to a string. For example, before storing the passwords in the database that the users enter in a web app, they can be converted into an array. Access to the data is made easier and more secure as a result. You can use arrays to achieve faster operations and better data organisation. PHP, a robust programming language, has several built-in methods for converting a string to an array.

In 2025, developers who can efficiently manipulate data, like converting strings to arrays in PHP, will be in high demand for building optimized web applications. If you’re looking to enhance your PHP and web development skills, here are some top-rated courses to help you get there:

• AI-Driven Full-Stack Development Bootcamp
• Master of Design in User Experience
• Professional Certificate Program in Cloud Computing and DevOps

There are basically four functions to convert String to Array in PHP:

Let’s implement each of these functions and see how they convert String to Array in PHP.

1. str_split()

str_split function converts a string to an array in PHP. It splits into bytes, rather than characters with a multi-byte encoded string.

Syntax:

str_split ( $string , $length )

Parameters:

String – The given Input string.
Length – The maximum string length.

If the length is mentioned, the returned array breaks down into chunks of that length number, else, the chunk length of each will be by default, one character.

If the measure of length is more than the length of the string, the complete string returns as the first array element.

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Example:

<?php

$str = "PHP String ”;

$arr1 = str_split($str);

$arr2 = str_split($str, 3);

print_r($arr1);

print_r($arr2);

?>

• $arr1 = str_split($str); splits the string into individual characters.
• $arr2 = str_split($str, 3); splits the string into chunks of 3 characters.

Output:

Array
(
   [0] => P
   [1] => H
   [2] => P
   [3] =>  
   [4] => S
   [5] => t
   [6] => r
   [7] => i
   [8] => n
   [9] => g
   [10] =>  
)

Array
(
   [0] => PHP
   [1] =>  St
   [2] => rin
   [3] => g 
)

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Also Read: Steps to Become a PHP Developer in 2025

2. preg_split()

preg_split is a function that splits a string using a regular expression.

Syntax:

preg_split ( $pattern ,  $subject ,  $limit ,  $flags )

Parameters:
Pattern – The string pattern to be searched.
Subject – The input string.
Limit – Substrings up to the limit value specified. A -1 or 0 means “no limit”.
Flags – If this flag is set, the appendant string offset is returned.

Example:

<?php

$string = preg_split("/[\s,]/", "hypertext programming language ");

print_r($string);

?>

• The string is split into individual words based on spaces (since \s matches any whitespace).
• The regular expression /[\s,]/ also includes commas, but since there are no commas in the string, it only splits by spaces.
• The last empty element in the array ([3] => ) is due to the trailing space at the end of the input string.

Output:

Array
(
[0] => hypertext
[1] => programming
[2] => language
)

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Also Read: Best PHP Project Ideas & Topics for Beginners in 2025

3. chunk_split()

chunk_split is a function that splits a string into a smaller chunk and returns a chunked string as an output.

Syntax:

chunk_split( $string , $length , $separator = “\r\n” )

Parameters:
String - The string to be chunked.
Length - The length of the chunk.
Separator - The ending line sequence.

Example:

<?php

$str = "Hello World!";

echo chunk_split($str,1,".");

?>

Output:

H.e.l.l.o. .w.o.r.l.d.!.

4. explode()

 explode is a PHP function that splits a string by a string. It is faster than the preg_split() function and is binary-safe.

Syntax:

explode ( $separator ,$string ,$limit)

Parameters:

Separator - The string at the boundary.
String - The input string.
Limit - Specifies the length of the output string

Note: If the limit is set to be a positive value, the returned array will be the maximum limit of elements with the last element having the remnant string. If the limit is a negative value, all the string components excluding the last limit are returned. If the limit is zero, then it is assumed as 1.

The explode function splits the string parameter on boundaries limited by the separator and returns an array. If the separator is an empty string (“), it returns a false value.

If the separator consists of some value that is not the part of the string and a negative limit is used, an empty array is returned, else an array of the string will be returned.

Example:

<?php

$input1 = "hello";

$input2 = "hello,world";

$input3 = ',';

print_r( explode( ',', $input1 ) );

print_r( explode( ',', $input2 ) );

print_r( explode( ',', $input3 ) );

?>

Output:

array(1)
(
[0] => string(5) "hello"
)
array(2)
(
[0] => string(5) "hello"
[1] => string(5) "there"
)
array(2)
(
[0] => string(0) ""
[1] => string(0) ""
)

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Also Read: Interface in PHP | PHP OOPs Interfaces

Next, let’s look at an alternative methods to convert String to Array in PHP.

Alternative Methods To Convert String To Array In PHP

Converting a string to array in PHP is essential for tasks like data parsing and processing user inputs. While common functions like explode(), str_split(), and preg_split() cover basic use cases, alternative methods such as substr(), array_map(), and custom logic offer greater flexibility for complex string manipulations. 

By exploring these alternatives, developers can choose the most efficient approach based on the specific needs of their project.

Here are some additional alternatives you can use to convert String to Array in PHP:

1. Manually Looping Through String

One alternative way to convert a string into an array in PHP is by manually looping through the string. This method gives you full control over how each character in the string is handled. It works by initializing a counter variable (like i) and iterating through the string until you've processed each character. You can then append each character to an array, ignoring spaces or handling them differently if needed.

This approach is useful when you want to perform additional operations during the string-to-array conversion, such as skipping certain characters or transforming data before adding it to the array.

Example Code:

<?php

$the_str = 'lorem ipsum';    
$the_ar = [];

for ($i = 0; $i < strlen($the_str); $i++) {
    if ($the_str[$i] != " ") { 
        $the_ar[] = $the_str[$i]; 
    }
}

echo "Final converted array: <br>";
print_r($the_ar); // l, o, r, e, m, i, p, s, u, m 

?>

Explanation:

• A variable $the_str holds the string to be converted, and $the_ar is an empty array where the result will be stored.
• The for loop runs through each character in the string using strlen($the_str) to get the length of the string.
• Inside the loop, if the current character is not a space ($the_str[$i] != " "), it is added to the array $the_ar.
• Finally, print_r() is used to display the contents of the array after conversion.

Output:

Final converted array: 
Array
(
   [0] => l
   [1] => o
   [2] => r
   [3] => e
   [4] => m
   [5] => i
   [6] => p
   [7] => s
   [8] => u
   [9] => m
)

Also Read: 12 Must-Have PHP Developer Skills for Success in 2025

2. Creating a Multidimensional Array from a String

To create a multidimensional array from a string, you can use the explode() function multiple times. This function splits a string based on a delimiter, allowing you to break down complex strings into smaller, more manageable pieces. 

For example, a string containing a person's full name and age can be split into a multidimensional array, where each piece of information (first name, last name, and age) is stored in a different part of the array.

Example Code:

<?php

$str = "Peter,Jacob,31";

// Split the string by commas
$arr1 = explode(",", $str); // $arr1 is now ["Peter", "Jacob", "31"]

// Split the first element (name) by space
$name = explode(" ", $arr1[0]); // $name is now ["Peter", "Jacob"]

// Extract age
$age = $arr1[2]; // $age is now "31"

// Create the multidimensional array
$newArr = [
    "first_name" => $name[0],
    "last_name" => $name[1],
    "age" => $age
];

print_r($newArr);

?>

Explanation:

• The explode(",", $str) splits the string into three parts: "Peter", "Jacob", and "31".
• Next, explode(" ", $arr1[0]) splits the first element of the array, "Peter", into two parts: "Peter" and "Jacob".
• The age is simply stored in the variable $age as "31".
• A new associative array, $newArr, is created, storing "first_name", "last_name", and "age" as keys, and the corresponding values as the split parts of the original string.

Output:
Array
(
   [first_name] => Peter
   [last_name] => Jacob
   [age] => 31
)

Using explode() multiple times allows you to easily transform a string into a multidimensional array, organizing related data into individual elements for easier manipulation and access. 

This approach is particularly useful when dealing with data in CSV-like formats or structured strings that require breaking down into distinct parts.

Also Read: Best PHP Developer Tools: Frameworks for Web Development

Next, let’s look at some of the best practices you can follow when converting String to Array in PHP.

Best Practices for Converting Strings to Arrays in PHP

Converting a string to an array is a fundamental task in PHP, commonly used for data parsing, form processing, and text manipulation. However, it's important to follow best practices to ensure that the conversion is done efficiently, avoiding errors and making the code easy to maintain.

Below are five best practices to follow when converting strings to arrays, along with examples showing why each practice is important:

1. Use explode() for Simple Delimited Strings

When dealing with strings that have clear delimiters (like commas, spaces, or semicolons), use explode() to split the string into an array. This function is simple, efficient, and widely used for handling structured data like CSVs or user input.

Example:

$string = "apple,banana,orange";
$array = explode(",", $string);
print_r($array); // ["apple", "banana", "orange"]

Why It Works? explode() is specifically designed to handle such use cases, making it the fastest and most efficient method for splitting strings by delimiters.

2. Handle Multiple Delimiters with preg_split()

When a string contains multiple delimiters or complex patterns (like spaces, commas, or special characters), preg_split() offers flexibility with regular expressions to handle diverse cases.

Example:

$string = "apple, orange; banana|grape";
$array = preg_split("/[\s,;|]+/", $string);
print_r($array); // ["apple", "orange", "banana", "grape"]

Why It Works? preg_split() allows you to use regular expressions to specify complex delimiters, making it ideal for cases where multiple delimiters or patterns need to be handled in a single operation.

3. Avoid str_split() for Complex Splits

While str_split() can be useful for splitting strings into fixed-length chunks, it's best suited for cases where each chunk is of equal length. For more complex splits (e.g., words or phrases), use other methods like explode() or preg_split().

Example:

$string = "hello world";
$array = str_split($string, 5);
print_r($array); // ["hello", " worl", "d"]

Why It Works? While str_split() is useful for breaking strings into fixed-length parts, it isn't ideal for splitting strings based on meaningful content like words or sentences. It can produce uneven results unless the string length is perfectly divisible by the chunk size.

4. Trim Unwanted Whitespace Before Converting

Always trim leading and trailing whitespace before splitting a string to prevent empty elements in your array. This is especially useful when dealing with user input or data that may contain extra spaces.

Example:

$string = "  apple, banana , orange  ";
$array = explode(",", trim($string));
print_r($array); // ["apple", "banana", "orange"]

Why It Works? By trimming the string first, you eliminate unwanted spaces that might cause empty array elements or incorrect data splitting, ensuring a cleaner and more predictable result.

5. Validate Input Data Before Conversion

Always validate and sanitize input data before performing any conversion. This ensures that the string is in the expected format and prevents errors or malicious input from breaking your code.

Example:

$string = "apple,orange,123";
if (preg_match("/^[a-zA-Z, ]*$/", $string)) {
   $array = explode(",", $string);
   print_r($array); // ["apple", "orange", "123"]
} else {
   echo "Invalid input.";
}

Why It Works? Validating input ensures that you’re working with the correct data type and format before converting it, reducing the risk of errors, such as unexpected characters, and improving the security and reliability of your application.

Also Read: PHP Developer Resume Examples & Writing Guide 2025

Next, let’s look at how upGrad can help you learn PHP programming.

How Can upGrad Help You Learn PHP Programming?

When converting strings into arrays in PHP, it’s crucial to choose the right method based on the data structure, ensure input validation, and handle delimiters effectively. These skills are essential for processing user input, parsing data, and building efficient web applications. 

Mastering these techniques with upGrad will enhance your problem-solving abilities and make you more attractive to employers, as PHP is widely used in web development. 

Along with the programs covered in the blog above, here are some additional courses to complement your learning journey:

• Learn Basic Python Programming
• Data Structures & Algorithms
• Java Object-oriented Programming
• JavaScript Basics from Scratch
• Advanced JavaScript for All

If you're unsure where to begin or which area to focus on, upGrad’s expert career counselors can guide you based on your goals. You can also visit a nearby upGrad offline center to explore course options, get hands-on experience, and speak directly with mentors!

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References:
https://app.studyraid.com/en/read/11843/376432/optimizing-performance-with-explode
https://stackoverflow.com/questions/5861826/performance-comparison-call-explode-in-foreach-signature-versus-passing-exp