3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(preg_match($r = '[foo\\[\\[[-.[:digit:][:space:]]+]', 'lorem foo[42 37 19 ] ipsum', $m), $m); echo "$r\n";
based on 5StQd
Output for 4.3.0 - 7.1.0
int(0) array(0) { } [foo\[\[[-.[:digit:][:space:]]+]