PHP recursively merge arrays while overwriting non-array values.

merge.php

<?php
/**
 * Recursively merge arrays, overwriting non-array values.
 *
 * @param array $first First array
 * @param array $second Second array
 * ...
 */
function array_merge_recursive_overwrite() {
    // Get all of our arguments
    $args = func_get_args();

    // Make sure we have arguments to work with
    if (count($args) < 2) return;

    // Handle more than 2 arrays
    if (count($args) > 2) {
        while (count($args) > 2) {
            $first = array_shift($args);
            $second = array_shift($args);
            array_unshift($args, array_merge_recursive_overwrite($first, $second));
        }

        $args = array_merge_recursive_overwrite($args[0], $args[1]);

        return $args;
    }

    $first = $args[0];
    $second = $args[1];

    foreach ($second as $key => $val) {
        if (isset($first[$key]) && is_array($first[$key])) {
            $val = array_merge_recursive_overwrite($first[$key], $val);
        }

        $first[$key] = $val;
    }

    return $first;
}