3v4l.org

run code in 300+ PHP versions simultaneously
<?php $consts = get_defined_constants(); $consts = array_keys($consts); usort($consts,function($a,$b){return strlen($a)<strlen($b);}); foreach($consts as $const){ echo strlen($const).": ".$const."\n"; }

preferences:
54.42 ms | 402 KiB | 5 Q