3v4l.org

run code in 300+ PHP versions simultaneously
<?php mb_internal_encoding('UTF-8'); $content = 'mesut kahveci'; if(!mb_check_encoding($content, 'UTF-8') OR !($content === mb_convert_encoding(mb_convert_encoding($content, 'UTF-32', 'UTF-8' ), 'UTF-8', 'UTF-32'))) { $content = mb_convert_encoding($content, 'UTF-8'); } echo mb_convert_case($content, MB_CASE_UPPER, "UTF-8");

preferences:
42.01 ms | 402 KiB | 5 Q