3v4l.org

run code in 300+ PHP versions simultaneously
<?php function permutation(array $arr) { while($ele=array_shift($arr)) { $x=$ele; echo $x."\n"; foreach($arr as $rest) { $x.=" $rest"; echo $x."\n"; } } } permutation(array("r","o","n","a","l","d","e"));

preferences:
54.15 ms | 402 KiB | 5 Q