php实现无限级分类，通过循环和递归实现

php无限极分类 

首先利用循环实现简单层次的展示

//使用PDO连接数据库

<?phpheader("content-type:text/html;charset=utf-8");$pdo = new PDO("mysql:host=127.0.0.1;dbname=ninthexam","root","root");$rs = $pdo -> query("select * from city");while($row = $rs -> fetch()){    $data[] = $row;}

//循环实现分类foreach($data as $k=>$v){    if($v['parint_id'] == 0)    {        $tmp[] = $v;        foreach($data as $key=>$value)        {            if($v['city_id'] == $value['parint_id'])            {                $tmp[] = $value;            }        }    }}echo "<pre>";print_r($tmp);

//在使用递归的方式实现无限极分类展示

 //使用递归实现无限极分类        function digui($data,$parint_id = 0 ,$cengji = 0)        {            //使用静态定义            static $tmp = array();            foreach($data as $k=>$v)            {                //判断如果“层级ID==自增ID”                if($v['parint_id'] == $parint_id)                {                    $v['cengji'] = $cengji;                    $tmp[] = $v;                    digui($data,$v['city_id'],$cengji+1);                }            }            return $tmp;        }

print_r(digui($data,$parint_id = 0 ,$cengji = 0));

以上便是实现简单无限级分类的几种方式，望采纳。