3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $x1 = $x2 = array(); $y = array('foo' => 'bar'); $x1 += $y; $x2 = array_merge($x2, $y); var_dump($x1); var_dump($x2);
based on MIOpl
Output for 4.3.0 - 5.6.30, hhvm-3.10.1 - 3.17.3, 7.0.0 - 7.2.0
array(1) { ["foo"]=> string(3) "bar" } array(1) { ["foo"]=> string(3) "bar" }