Recursive RBAC menu level display infinite classification

  recursive ： Call yourself , And there is a recursive exit , End recursion

    function rbac($node,$pid=0,$level=1)
    {
        static $arr = [];
        foreach ($node as $val) {
            if ($val['pid'] == $pid) {
                $val['level'] = $level;
                $arr[] = $val;
                rbac($node, $val['nid'], $level + 1);
            }
        }
        return $arr;
    }