3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(preg_match('/(?<=^| |,|\(|\))(\d+(?:px|pt|em|%|ex|cm|mm|in|pc)) ((?1)) (?1) \2(?=$| |,|\(|\))/', '15px 5px 10px 5px'));
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
int(1)