<?phpheader("Content-Type:text/html;charset=utf-8");/*无限级分类。牵扯2个应用0是-找指定栏目的子栏目1是-找指定栏目的子孙栏目，即子孙树2是-找指定栏目的父栏目/父父栏目....顶级栏目，即家谱树*/$aarr=array(array('id'=>1,'name'=>'安徽','pid'=>0),array('id'=>2,'name'=>'海淀','pid'=>7),array('id'=>3,'name'=>'浣溪县','pid'=>5),array('id'=>4,'name'=>'昌平','pid'=>7),array('id'=>5,'name'=>'淮北','pid'=>1),array('id'=>6,'name'=>'朝阳','pid'=>7),array('id'=>7,'name'=>'北京','pid'=>0),array('id'=>8,'name'=>'上地','pid'=>2));//用到静态变量，找子孙树functionsubtree($arr,$id=0,$lev=1){static$subs=array();//子孙数组foreach($arras$v){if($v['pid']==$id){$v['lev']=$lev;$subs[]=$v;////举例说找到array('id'=>1,'name'=>'安徽','pid'=>0);subtree($arr,$v['id'],$lev+1);//让他递归遍历里面的数组}}return$subs;}//echo"<pre>";//print_r(subtree($aarr,0,1));$tree=subtree($aarr,0,1);foreach($treeas$v){echostr_repeat('&nbsp;&nbsp;&nbsp;',$v['lev']).$v['name'].'<br/>';}