3v4l.org

run code in 300+ PHP versions simultaneously
<?php $ids=array(array("a","s"),array("b","s"), array("c","s"), array("e","s")); $groups=array(array("b","s"),array("c","s")); array_walk($groups,function($v,$i)use(&$ids){ $ids=array_intersect ($ids,$v); }); print_r($ids);

preferences:
36.19 ms | 402 KiB | 5 Q