PHP How to Convert String to Array Easily

In PHP, you can convert a string to an array using explode(separator, string) to split by a delimiter or str_split(string) to split into characters.

Examples

Input"apple,banana,orange"

Output["apple", "banana", "orange"]

Input"hello"

Output["h", "e", "l", "l", "o"]

Input"one|two|three"

Output["one", "two", "three"]

How to Think About It

To convert a string to an array, first decide how you want to split it: by a specific character like a comma or by each character. Use explode if you have a clear separator, or str_split to split every character into array elements.

Algorithm

1

Get the input string.

2

Decide the splitting method: by delimiter or by characters.

3

If splitting by delimiter, use explode with the delimiter and string.

4

If splitting by characters, use str_split with the string.

5

Return the resulting array.

Code

php

<?php
// Convert string to array by delimiter
$string = "apple,banana,orange";
$array = explode(",", $string);
print_r($array);

// Convert string to array by characters
$string2 = "hello";
$array2 = str_split($string2);
print_r($array2);
?>

Output

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)
Array
(
    [0] => h
    [1] => e
    [2] => l
    [3] => l
    [4] => o
)

Dry Run

Let's trace converting "apple,banana,orange" to an array using explode.

1

Input string

string = "apple,banana,orange"

2

Call explode

explode(",", string) splits string at each comma

3

Result array

["apple", "banana", "orange"]

Iteration	Current Part
1	apple
2	banana
3	orange

Why This Works

Step 1: Using explode

explode splits the string at each occurrence of the delimiter and returns an array of parts.

Step 2: Using str_split

str_split breaks the string into single characters, each becoming an array element.

Alternative Approaches

preg_split

php

<?php
$string = "one,two;three four";
$array = preg_split('/[ ,;]+/', $string);
print_r($array);
?>

Use <code>preg_split</code> to split by multiple delimiters using regular expressions, but it's slower than explode.

mb_str_split

php

<?php
$string = "héllo";
$array = mb_str_split($string);
print_r($array);
?>

Use <code>mb_str_split</code> for multibyte-safe splitting into characters, useful for UTF-8 strings.

Complexity: O(n) time, O(n) space

Time Complexity

Splitting the string requires scanning each character once, so time is proportional to string length, O(n).

Space Complexity

The output array stores parts or characters, so space used grows with string length, O(n).

Which Approach is Fastest?

explode is fastest for simple delimiter splits; str_split is efficient for character splits; preg_split is slower due to regex overhead.

Approach	Time	Space	Best For
explode	O(n)	O(n)	Splitting by single delimiter
str_split	O(n)	O(n)	Splitting into characters
preg_split	O(n)	O(n)	Splitting by multiple delimiters or patterns
mb_str_split	O(n)	O(n)	Splitting multibyte UTF-8 characters