- var_dump: documentation ( source)
- array_merge: documentation ( source)
<?php
$array1 = array(
'a' => 1,
'b' => 2,
);
$array2 = array(
'b' => 22,
'c' => 3,
);
var_dump(array_merge($array1, $array2));
var_dump($array1 + $array2);
var_dump($array2 + $array1);