3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php preg_match('/^\/validation\/(?P<user_name>\w+)?\/(?P<user_key>\w+)?\/$/', "validation/aa/1/",$matches); print_r($matches); echo "\n";
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
Array ( )