3v4l.org

run code in 300+ PHP versions simultaneously
<?php //echo preg_replace('/(?:(?!dog).)++/', '<$0>', 'where my dog is now?'); echo preg_replace('/(?!ba).|(*SKIP)ba(*F)/', '<$0>', 'aabaabaaaaabbb');

preferences:
38.42 ms | 402 KiB | 5 Q