3v4l.org

run code in 300+ PHP versions simultaneously
<?php $v = 'potato'; $file = ' blah blah potatos blah pomidoros blah potato blah potato bbb blue fadf uuu there is a potato too!! hah! potato.'; echo preg_match_all("~\b{$v}\b~",$file);

preferences:
54.77 ms | 402 KiB | 5 Q