How to Convert Number to Character Array in PHP ?

Given a number, the task is to convert numbers to character arrays in PHP. It is a common operation when you need to manipulate or access individual digits of a number.

This can be particularly useful in situations where you need to perform operations on the digits of a number, such as digital root calculations, digit summing, or validations.

Below are the approaches to convert numbers to character arrays in PHP:

Using str_split() Function

The str_split() function is one of the simplest ways to convert a string into an array of characters. To use it with numbers, you first need to convert the number to a string and then use str_split() to split the string into array of characters.

Example: This example shows the use of the above-explained approach.

<?php

$number = 12345;

// Convert number to string and
// then to character array
$charArray = str_split((string)$number);

print_r($charArray);

?>

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)

Using Manual Conversion with Loop

A number can be converted to a character array by iterating over each digit. This method gives you more control over the conversion process. First, we convert the integer into a string and then we use for loop to iterate it.

Example: This example shows the use of the above-explained approach.

<?php
  
$number = 12345;
$numberStr = (string)$number;
$charArray = [];

// Loop through each character of the string
for($i = 0; $i < strlen($numberStr); $i++) {
    // Add each digit to the array
    $charArray[] = $numberStr[$i];
}

print_r($charArray);

?>

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)

Using preg_split() Function

The preg_split() function is primarily used for splitting strings based on a regular expression pattern.

• ' // ': This empty regular expression pattern matches between each character in the string, effectively splitting it into individual characters.
• ' -1 ': Indicates that there is no limit to the number of splits that can be performed.
• PREG_SPLIT_NO_EMPTY: This flag tells preg_split() not to return empty matches. In this case, it ensures that consecutive digits are treated as separate elements in the resulting array.

Example: This example shows the use of the above-explained approach.

<?php

$number = 12345;
$numberAsString = (string) $number;

// preg_split() splits the string according to the regular expression pattern
$charArray = preg_split('//', $numberAsString, -1, PREG_SPLIT_NO_EMPTY);

print_r($charArray);

?>

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)