3v4l.org

run code in 500+ PHP versions simultaneously
<?php $array1 = ['x' => 1, 3 => 4, 't' => 8]; $array2 = ['x' => 2, 5 => 6,]; $array3 = ['x' => [3, 4, 5]]; $array4 = ['x' => [[4]]]; $arrays = [$array1, $array2, $array3, $array4]; print_r(array_merge_recursive(...$arrays));
Output for 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.21, 8.5.0 - 8.5.6
Array ( [x] => Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => Array ( [0] => 4 ) ) [0] => 4 [t] => 8 [1] => 6 )
preferences:
42.28 ms | 871 KiB | 4 Q