php方法参数里传数组

function getCatTree(Array $items) {

    $tree = array();

    foreach ($items as $item)

    if (isset($items[$item['parent_id']])) {

        $items[$item['parent_id']]['son'][] = &$items[$item['id']];

    } else {

        $tree[] = &$items[$item['id']];

}

dump($tree);

    return $tree;

}