PHP获取无限极分类

<?php 
    static public function unlimitedForLevel($cate,$html='|—',$pid=0,$level=0){
        //建立空数组存储结果
        $arr = array();
        //循环$cate，如果这级的pid等于上一级的cid，就先压入数组，再找当前的下一级
        foreach ($cate as $v) {
            //查找当前分类是否有子分类
            if ($v['parent_id'] == $pid) {
                $v['level'] = $level + 1;
                $v['html'] = str_repeat($html, $level);

                $arr[] = $v;
                //递归合并数组
                $arr = array_merge($arr,self::unlimitedForLevel($cate,$html,$v['id'],$level+1));
            }
        }
        return $arr;
    }

    //静态方法获取多维数组递归结果
    static public function unlimitedForMore($cate,$name='child',$pid=0){
        $arr = array();
        foreach ($cate as $v) {
            if ($v['parent_id'] == $pid) {
                $v[$name] = self::unlimitedForMore($cate,$name,$v['id']);
                $arr[] = $v;
            }
        }
        return $arr;
    }

    //递归获取父函数
    static public function getParents($cate,$cid){
        $arr = array();
        foreach ($cate as $v) {
            if ($v['id'] == $cid) {
                $arr[] = $v;
                $arr = array_merge(self::getParents($cate,$v['parent_id']),$arr);
            }
        }
        return $arr;
    }

 ?>