无限极分类

来源 ：https://www.cnblogs.com/hualingyun/p/16364375.html

private function getChildBak($data,$parent_id = 0){
        $arr=array();
        $i = 0; 
        foreach($data as $val){ 
            if($val['pId']==$parent_id){ 
    
                $val['label'] = $val['name'];
                $arr[$i]=$val;
                $son=$this->getChildBak($data,$val['id']);
                $arr[$i]['children']=$son;
                $i++;
            }
        }
        return $arr;
    }