php如何删除数组

<?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();
}