php 无限分类 并生成树状图

$yArr    = array(
     1 => array('id'=>'1','parentid'=>0,'name'=>'一级栏目一'),
     2 => array('id'=>'2','parentid'=>0,'name'=>'一级栏目二'),
     3 => array('id'=>'3','parentid'=>1,'name'=>'二级栏目一'),
     4 => array('id'=>'4','parentid'=>1,'name'=>'二级栏目二'),
     5 => array('id'=>'5','parentid'=>2,'name'=>'二级栏目三'),
     6 => array('id'=>'6','parentid'=>3,'name'=>'三级栏目一'),
     7 => array('id'=>'7','parentid'=>3,'name'=>'三级栏目二'),
     8 => array('id'=>'8','parentid'=>2,'name'=>'二级栏目三'),
 );
 
 /**
  * 获取当前id的子ID
  * @param array $data 原始数组
  * @param int $id 当前id
  * @param int $layer 当前层级
  */
 function genCate($data, $pid = 0, $level = 0)
 {
     $l        = str_repeat("    ", $level);
     $l        = $l.'└';
     static $arrcat    = array();
     $arrcat    = empty($level) ? array() : $arrcat;
     foreach($data as $k => $row)
     {
         /**
          * 如果父ID为当前传入的id
          */
         if($row['parentid'] == $pid)
         {
             //如果当前遍历的id不为空
             $row['name']    = $l.$row['name'];
             $row['level']    = $level;
             $arrcat[]    = $row;
             //var_array($arr);
             genCate($data, $row['id'], $level+1);//递归调用
         }
     }
     return $arrcat;
 }
 
 $carr    = genCate($yArr);
 echo "<select>";
 foreach($carr as $row)
 {
     echo "<option value={$row['id']}>";
     echo $row['name'];
     echo "</option>";
 }
 echo "</select>";