3v4l.org

run code in 300+ PHP versions simultaneously
<?php $source = ["a" => 1, "b" => 2, "c" => 3]; $input = ["d" => 4, "b" => 10]; $new = $source + ($source + $input); print_r($new);
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
Array ( [a] => 1 [b] => 2 [c] => 3 [d] => 4 )
preferences:
97.73 ms | 407 KiB | 5 Q