PHP统计Json数据节点中数据总和

    function get_tree_level($tree_data)
    {
        $level = 0;
        $max_lvl = 0;

        $str = $tree_data;
        while($str = strstr($str, "\"value\":\""))
        {
            $str = substr($str, 9); //"value":"
            $idx = 0;
            $level = 0;
            $comma_str = strstr($str, ",");
            $segstr = substr($str,0,strlen($str)-strlen($comma_str));
            $ars = explode("/", $segstr);
            $level = count($ars);

            if($level > $max_lvl)
            {
                $max_lvl = $level;
            }

            $str = substr($str, $idx);
        }

        return $max_lvl;
    }


    function add_node_nums($json_cont, $parent_id, $numb)
    {