php如何删除多维数组

<?php
$arr = [
    'test' => 'value',
    'level_one' => [
        'level_two' => [
            'level_three' => [
                'replace_this_array' => [
                    'special_key' => 'replacement_value',
                    'key_one' => 'testing',
                    'key_two' => 'value',
                    'four' => 'another value',
                ],
            ],
            'ordinary_key' => 'value',
        ],
    ],
];
$unset = array('special_key', 'ordinary_key', 'four');
echo "<pre>";
print_r(unsetMultiKeys($unset, $arr));
print_r($arr);
echo "</pre>";
exit;
function unsetMultiKeys($unset, $array) {
    $arrayIterator = new \RecursiveArrayIterator($array);
    $recursiveIterator = new \RecursiveIteratorIterator($arrayIterator, \RecursiveIteratorIterator::SELF_FIRST);
    foreach ($recursiveIterator as $key => $value) {
        foreach ($unset as $v) {
            if (is_array($value) && array_key_exists($v, $value)) {
                // 删除不要的值
                unset($value[$v]);
                // Get the current depth and traverse back up the tree, saving the modifications
                $currentDepth = $recursiveIterator->getDepth();
                for ($subDepth = $currentDepth; $subDepth >= 0; $subDepth--) {
                    // Get the current level iterator
                    $subIterator = $recursiveIterator->getSubIterator($subDepth);
                    // If we are on the level we want to change, use the replacements ($value) other wise set the key to the parent iterators value
                    $subIterator->offsetSet($subIterator->key(), ($subDepth === $currentDepth ? $value : $recursiveIterator->getSubIterator(($subDepth + 1))->getArrayCopy()));
                }
            }
        }
    }
    return $recursiveIterator->getArrayCopy();
}