3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 'Ukraine - Russia or Iran - Argentina'; preg_match('/([ ]*[-]?[ ]*){1}(or){1}/', $a, $m); var_dump($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, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.12 - 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(3) { [0]=> string(3) " or" [1]=> string(1) " " [2]=> string(2) "or" }

preferences:
205.22 ms | 405 KiB | 350 Q