3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump(preg_match('\d{4}', 2013));
Output for 4.3.11 - 4.4.5, 4.4.7 - 7.2.0
Warning: preg_match(): Delimiter must not be alphanumeric or backslash in /in/jupf0 on line 2 bool(false)
Output for 4.4.6

Process exited with code 143.
Output for 4.3.0 - 4.3.10
Warning: Delimiter must not be alphanumeric or backslash in /in/jupf0 on line 2 bool(false)