3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a1 = ['foo' => 'bar', 'baz' => null]; $a2 = ['foo' => 'baf', 'baz' => 'lalala', 'bam' => 2]; var_dump($a1 + $a2); var_dump(array_merge($a1, $a2));
Output for 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 - 8.2.19, 8.3.0 - 8.3.7
array(3) { ["foo"]=> string(3) "bar" ["baz"]=> NULL ["bam"]=> int(2) } array(3) { ["foo"]=> string(3) "baf" ["baz"]=> string(6) "lalala" ["bam"]=> int(2) }
preferences:
256.14 ms | 404 KiB | 329 Q