3v4l.org

run code in 300+ PHP versions simultaneously
<?php $h = "asdasd __asdasd__ frer __ desg df -+ br __"; preg_match_all('/_\_(.*?)_\_/i', $h, $r, PREG_PATTERN_ORDER); print_r($r);
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 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Array ( [0] => Array ( [0] => __asdasd__ [1] => __ desg df -+ br __ ) [1] => Array ( [0] => asdasd [1] => desg df -+ br ) )

preferences:
242.62 ms | 406 KiB | 460 Q