3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [1 => 1, 2 => 2, 3 => 3]; $b = [4 => 4, 5 => 5, 6 => 6]; $a += $b; var_dump($a);

preferences:
34.52 ms | 402 KiB | 5 Q