mb_str_split

(PHP 7 >= 7.4.0, PHP 8)

mb_str_split — Given a multibyte string, return an array of its characters

Description

mb_str_split(string $string, int $length = 1, ?string $encoding = null): array

This function will return an array of strings, it is a version of str_split() with support for encodings of variable character size as well as fixed-size encodings of 1,2 or 4 byte characters. If the length parameter is specified, the string is broken down into chunks of the specified length in characters (not bytes). The encoding parameter can be optionally specified and it is good practice to do so.

Parameters

string

The string to split into characters or chunks.

length

If specified, each element of the returned array will be composed of multiple characters instead of a single character.

encoding

The encoding parameter is the character encoding. If it is omitted or null, the internal character encoding value will be used.

A string specifying one of the supported encodings.

Return Values

mb_str_split() returns an array of strings.

Changelog

Version	Description
8.0.0	`encoding` is nullable now.
8.0.0	This function no longer returns `false` on failure.

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User Contributed Notes 2 notes

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info at ensostudio dot ru ¶

4 years ago

Note: function return NULL if can't convert argument type.

Polyfill PHP < 7.4 based on package "symfony/polyfill-mbstring":
<?php
function mb_str_split($string, $split_length = 1, $encoding = null)
{
    if (null !== $string && !\is_scalar($string) && !(\is_object($string) && \method_exists($string, '__toString'))) {
        trigger_error('mb_str_split(): expects parameter 1 to be string, '.\gettype($string).' given', E_USER_WARNING);
        return null;
    }
    if (null !== $split_length && !\is_bool($split_length) && !\is_numeric($split_length)) {
        trigger_error('mb_str_split(): expects parameter 2 to be int, '.\gettype($split_length).' given', E_USER_WARNING);
        return null;
    }
    $split_length = (int) $split_length;
    if (1 > $split_length) {
        trigger_error('mb_str_split(): The length of each segment must be greater than zero', E_USER_WARNING);
        return false;
    }
    if (null === $encoding) {
        $encoding = mb_internal_encoding();
    } else {
        $encoding = (string) $encoding;
    }
    
    if (! in_array($encoding, mb_list_encodings(), true)) {
        static $aliases;
        if ($aliases === null) {
            $aliases = [];
            foreach (mb_list_encodings() as $encoding) {
                $encoding_aliases = mb_encoding_aliases($encoding);
                if ($encoding_aliases) {
                    foreach ($encoding_aliases as $alias) {
                        $aliases[] = $alias;
                    }
                }
            }
        }
        if (! in_array($encoding, $aliases, true)) {
            trigger_error('mb_str_split(): Unknown encoding "'.$encoding.'"', E_USER_WARNING);
            return null;
        }
    }
    
    $result = [];
    $length = mb_strlen($string, $encoding);
    for ($i = 0; $i < $length; $i += $split_length) {
        $result[] = mb_substr($string, $i, $split_length, $encoding);
    }
    return $result;
}
?>