3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $r1 = '/(?!<\\\\)\\\\n/'; $r2 = '((?:\\\\(*SKIP)(*FAIL))\\\\n)'; var_dump(preg_match($r1, "\\\\\\\\\n"));
Output for 4.3.0 - 7.1.0
int(0)