3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php print_r(array_merge(null, array(1,2)));
based on kpmEu
Output for 5.0.0 - 7.2.0
Warning: array_merge(): Argument #1 is not an array in /in/KJC58 on line 3
Output for 4.3.0 - 4.4.9
Array ( [0] => 1 [1] => 2 )