PHP 根据key 给二维数组分组

Array
(
    [0] => Array
        (
            [id] => 1
            [wo_id] => 2
            [evaluate_id] => 1
            [type] => 分组1
            [ctime] => 2016-12-02 11:39:34
        )

    [1] => Array
        (
            [id] => 2
            [wo_id] => 31
            [evaluate_id] => 2
            [type] => 分组1
            [ctime] => 2016-12-12 11:39:50
        )

    [2] => Array
        (
            [id] => 3
            [wo_id] => 31
            [evaluate_id] => 4
            [type] => 分组2
            [ctime] => 2016-12-02 11:40:01
        )

    [3] => Array
        (
            [id] => 4
            [wo_id] => 2
            [evaluate_id] => 5
            [type] => 分组2
            [ctime] => 2016-12-07 10:21:40
        )

    [4] => Array
        (
            [id] => 5
            [wo_id] => 2
            [evaluate_id] => 3
            [type] => 分组2
            [ctime] => 2016-12-07 10:21:51
        )

    [5] => Array
        (
            [id] => 6
            [wo_id] => 2
            [evaluate_id] => 2
            [type] => 分组3
            [ctime] => 2016-12-07 10:21:56
        )

    [6] => Array
        (
            [id] => 7
            [wo_id] => 4
            [evaluate_id] => 2
            [type] => 分组3
            [ctime] => 2016-12-07 10:22:10
        )
)

这里是一个很典型的例子，如果我希望把 数组中的数据 根据 type（分组） 分开处理，如果不分组，可能循环上会非常冗余，所以有了下面的一个分组函数：

public static function array_group_by($arr, $key)
    {
        $grouped = [];
        foreach ($arr as $value) {
            $grouped[$value[$key]][] = $value;
        }
        // Recursively build a nested grouping if more parameters are supplied
        // Each grouped array value is grouped according to the next sequential key
        if (func_num_args() > 2) {
            $args = func_get_args();
            foreach ($grouped as $key => $value) {
                $parms = array_merge([$value], array_slice($args, 2, func_num_args()));
                $grouped[$key] = call_user_func_array('array_group_by', $parms);
            }
        }
        return $grouped;
    }

$arr : 二维数组

$key: 需要分组的key

得到的结果是：

Array
(
    [分组2] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [wo_id] => 2
                    [evaluate_id] => 1
                    [ctime] => 2016-12-02 11:39:34
                    [type] => 分组2
                )

            [1] => Array
                (
                    [id] => 2
                    [wo_id] => 31
                    [evaluate_id] => 2
                    [ctime] => 2016-12-12 11:39:50
                    [type] => 分组2
                )

            [2] => Array
                (
                    [id] => 3
                    [wo_id] => 31
                    [evaluate_id] => 4
                    [ctime] => 2016-12-02 11:40:01
                    [type] => 分组2
                )

        )

    [分组1] => Array
        (
            [0] => Array
                (
                    [id] => 4
                    [wo_id] => 2
                    [evaluate_id] => 5
                    [ctime] => 2016-12-07 10:21:40
                    [type] => 分组1
                )

            [1] => Array
                (
                    [id] => 5
                    [wo_id] => 2
                    [evaluate_id] => 3
                    [ctime] => 2016-12-07 10:21:51
                    [type] => 分组1
                )
        )
)