3v4l.org

run code in 300+ PHP versions simultaneously
<?php preg_match("/(\w+)?/", "",$matches); print_r($matches); echo "\n"; preg_match("/(\w*)/", "",$matches); print_r($matches);
Output for 4.3.0, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 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] => [1] => )

preferences:
271.64 ms | 404 KiB | 412 Q