3v4l.org

run code in 300+ PHP versions simultaneously
<?php $regex = '-(\d+)-(\w+)@(mailing.)?kingsquare.nl$'; echo (preg_match('/' . $regex . '/i', 'mirolscom-17999782-9342797@mailing.kingsquare.nl'));

preferences:
41.59 ms | 402 KiB | 5 Q