3v4l.org

run code in 300+ PHP versions simultaneously
<?php function doIt($string, $charset) { echo mb_strtoupper(mb_substr($string, 0, 1, $charset), $charset).mb_strtolower(mb_substr($string, 1, 2147483647, $charset), $charset), "\n"; } doIt('abcd', 'UTF-8'); doIt('abcd', 'ASCII'); doIt('abcd', 'ISO-8859-15');
Output for 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Abcd Abcd Abcd
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.30, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33
Abcd A A
preferences:
266.47 ms | 404 KiB | 369 Q