3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [ 'a' => 'A', 'b' => 'B', 3 => 'THREE', 4 => 'FOUR' ]; $b = [ 'b' => 'another-B', 'c' => 'C', 4 => 'another-FOUR' ]; var_dump(array_merge($a, $b)); var_dump(array_replace($a, $b));
Output for 8.2.0 - 8.2.29, 8.3.0 - 8.3.27, 8.4.1 - 8.4.14
array(6) { ["a"]=> string(1) "A" ["b"]=> string(9) "another-B" [0]=> string(5) "THREE" [1]=> string(4) "FOUR" ["c"]=> string(1) "C" [2]=> string(12) "another-FOUR" } array(5) { ["a"]=> string(1) "A" ["b"]=> string(9) "another-B" [3]=> string(5) "THREE" [4]=> string(12) "another-FOUR" ["c"]=> string(1) "C" }
preferences:
47.89 ms | 407 KiB | 5 Q