3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr=array("aa", "az", "an","am", "ba", "by", "alien","i"); usort($arr, function ($a, $b) { return strlen($a) == strlen($b) ? $a <=> $b : strlen($a) <=> strlen($b); }); print_r($arr);
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Array ( [0] => i [1] => aa [2] => am [3] => an [4] => az [5] => ba [6] => by [7] => alien )

preferences:
126.77 ms | 402 KiB | 117 Q