merge-array-recursive.php

<?php

$arr1 = array(
	"a" => ["x", "d" => "override me..",  "d2" => ["q"], "v" => "NOT-IN-B"],
	"b" => ["d" => 155, "fff" => ["aa"=>551]],
	5, 8, 9
);

$arr2 = array(
	"a" => ["v", "d" => "overrided!", "qq" => "ONLY-IN-B"],
	"b" => ["xxx" => 155, "fff" => ["aa"=>552]],
	5, 7
);

function merge_array_recursive($a, $b) {
	$new =& $b;

	function deepMerge($a, &$new) {
		foreach($a as $kA1 => $vA1) {
			if (!isset($new[$kA1])) {
				$new[$kA1] = $vA1;
			}
			if (is_array($vA1) && is_array($new[$kA1])) {
				deepMerge($vA1, $new[$kA1]);
			}
		}
	}
	deepMerge($a, $b);

	return $new;
}

$res = merge_array_recursive($arr1, $arr2);

echo '<pre>';
print_r($res);
?>