3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php preg_match('/(?>[A-Za-z])+([A-Za-z])+/', 'FooBar', $m); var_dump($m); preg_match('/([A-Za-z])++([A-Za-z])+/', 'FooBar', $m); var_dump($m);
based on RoP3a
Output for 4.3.0 - 7.1.0
array(2) { [0]=> string(6) "FooBar" [1]=> string(1) "r" } array(0) { }