Multibyte Similar Text for PHP, mb_similar_text()

mb_similar_text.php

<?php
/*
 * solves the problem at http://stackoverflow.com/questions/31002690/how-to-use-similar-text-php-code-in-arabic, not that I know Arabic, but Norwegian also has multibyte charachters: æøåÆØÅ
 */
//from http://www.phperz.com/article/14/1029/31806.html
function mb_split_str($str) {
    preg_match_all("/./u", $str, $arr);
    return $arr[0];
}

//based on http://www.phperz.com/article/14/1029/31806.html, added percent
function mb_similar_text($str1, $str2, &$percent) {
    $arr_1 = array_unique(mb_split_str($str1));
    $arr_2 = array_unique(mb_split_str($str2));
    $similarity = count($arr_2) - count(array_diff($arr_2, $arr_1));
    $percent = ($similarity * 200) / (strlen($str1) + strlen($str2) );
    return $similarity;
}

//demo:
//$var = mb_similar_text('عمار', 'ياسر', $per);
//output: $var = 2, $per = 25