reverse multibyte strings in PHP

mb_strrev.php

<?php

// http://kvz.io/blog/2012/10/09/reverse-a-multibyte-string-in-php/
function mb_strrev ($string, $encoding = null) {
	if ($encoding === null) {
		$encoding = mb_detect_encoding($string);
	}

	$length   = mb_strlen($string, $encoding);
	$reversed = '';
	while ($length-- > 0) {
		$reversed .= mb_substr($string, $length, 1, $encoding);
	}

	return $reversed;
}