mb_str_split.php

<?php

/**
 * Replacement of str_split() function with multi-byte encoding support.
 *
 * @param string $string     The input string.
 * @param int $string_length [optional] Maximum length of the chunk.
 * @param string $charset    Character encoding.
 *
 * @return array
 */
function mb_str_split($string, $string_length = 1, $charset = 'utf-8')
{
    if (mb_strlen($string, $charset) > $string_length || !$string_length) {
        do {
            $c = mb_strlen($string, $charset);
            $parts[] = mb_substr($string, 0, $string_length, $charset);
            $string = mb_substr($string, $string_length, $c - $string_length, $charset);
        } while (!empty($string));
    } else {
        $parts = array($string);
    }
    return $parts;
}