php无限极分类

Array
(
    [0] => Array
        (
            [worksheet_name] => 第一级
            [worksheet_id] => 1
            [worksheet_parent_id] => 0
        )

    [1] => Array
        (
            [worksheet_name] => 第二级
            [worksheet_id] => 2
            [worksheet_parent_id] => 0
        )

    [2] => Array
        (
            [worksheet_name] => 第三级
            [worksheet_id] => 3
            [worksheet_parent_id] => 3
        )

    [3] => Array
        (
            [worksheet_name] => 第四级
            [worksheet_id] => 4
            [worksheet_parent_id] => 3
        )

    [4] => Array
        (
            [worksheet_name] => 第五级
            [worksheet_id] => 5
            [worksheet_parent_id] => 2
        )

    [5] => Array
        (
            [worksheet_name] => 第六级
            [worksheet_id] => 6
            [worksheet_parent_id] => 0
        )

    [6] => Array
        (
            [worksheet_name] => 第七级
            [worksheet_id] => 7
            [worksheet_parent_id] => 3
        )

    [7] => Array
        (
            [worksheet_name] => 第八级
            [worksheet_id] => 8
            [worksheet_parent_id] => 1
        )

    [8] => Array
        (
            [worksheet_name] => 第九级
            [worksheet_id] => 10
            [worksheet_parent_id] => 6
        )

    [9] => Array
        (
            [worksheet_name] => 第十级
            [worksheet_id] => 12
            [worksheet_parent_id] => 6
        )

    [10] => Array
        (
            [worksheet_name] => 十一级
            [worksheet_id] => 14
            [worksheet_parent_id] => 0
        )

    [11] => Array
        (
            [worksheet_name] => 十二级
            [worksheet_id] => 16
            [worksheet_parent_id] => 12
        )

    [12] => Array
        (
            [worksheet_name] => 十三级
            [worksheet_id] => 17
            [worksheet_parent_id] => 7
        )

    [13] => Array
        (
            [worksheet_name] => 十四级
            [worksheet_id] => 18
            [worksheet_parent_id] => 7
        )

    [14] => Array
        (
            [worksheet_name] => 十五级
            [worksheet_id] => 19
            [worksheet_parent_id] => 9
        )

    [15] => Array
        (
            [worksheet_name] => 十六级
            [worksheet_id] => 20
            [worksheet_parent_id] => 9
        )

    [16] => Array
        (
            [worksheet_name] => 十七级
            [worksheet_id] => 21
            [worksheet_parent_id] => 0
        )

    [17] => Array
        (
            [worksheet_name] => 十八级
            [worksheet_id] => 22
            [worksheet_parent_id] => 0
        )

    [18] => Array
        (
            [worksheet_name] => 十九级
            [worksheet_id] => 23
            [worksheet_parent_id] => 16
        )

    [19] => Array
        (
            [worksheet_name] => 二十级
            [worksheet_id] => 24
            [worksheet_parent_id] => 23
        )

)

上面数组是普通的二维数组 ,仅供参考  下面代码实现方式

function getList($list, $worksheet_parent_id=0,$level=0){
    static $arr=array();
    foreach ($list as $k =>$v){
        if($v['worksheet_parent_id']==$worksheet_parent_id){
            $v['level']=$level;
            $arr[]=$v;
            getList($list,$v['worksheet_id'],$level+3);
        }
    }
    return  $arr;
 }

如何展示