3v4l.org

run code in 200+ php & hhvm versions
<?php $array = array_merge([1,2], [3,4]); sort($array); var_dump($array);
based on 3HTmt
Output for 7.1.25 - 7.3.5
array(4) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(4) }