- Output for 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
- AAaaĄaśćŻŹ
<?php
$string = 'aaAAąAŚĆżź';
echo preg_replace_callback(
'/(\p{Lu})|(\p{Ll})/u',
function($m) {
return $m[1]
? mb_strtolower($m[1])
: mb_strtoupper($m[2]);
},
$string
);