3v4l.org

run code in 300+ PHP versions simultaneously
<?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);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
array(0) { } array(0) { }

preferences:
208.02 ms | 405 KiB | 309 Q