PHP根据键的值拆分和组合数组

Question

以下是示例数组：

Array
(
    [0] => Array
        (
            [action] => move
            [para1] => h_1
            [para2] => loc_231
            [day] => day_1
        )

    [1] => Array
        (
            [action] => visit
            [para1] => poi_231
            [para2] => loc_231
            [day] => day_1

        )
     [2] => Array
        (
            [action] => visit
            [para1] => poi_231
            [para2] => loc_231
            [day] => day_2

        )
   )

我想根据键day的值拆分数组，然后将它们组合在一起。

最终数组应如下所示：

    Array
    (
        Array(
         [0] => Array
            (
                [action] => move
                [para1] => h_1
                [para2] => loc_231
                [day] => day_1
            )

        [1] => Array
            (
                [action] => visit
                [para1] => poi_231
                [para2] => loc_231
                [day] => day_1

            )
       )
      Array(
        [0] => Array
            (
                [action] => visit
                [para1] => poi_231
                [para2] => loc_231
                [day] => day_2

            )
      )

 )

除了遍历数组之外，有什么更好的方法？是否有任何PHP功能？

Answer 1

你可以自己动手

$data = array(array("action"=>"1","day"=>"day_2"),array("action"=>"2","day"=>"day_1"),array("action"=>"3","day"=>"day_1"),array("action"=>"4","day"=>"day_2"),array("action"=>"5","day"=>"day_1"));
print_r($data);
function split_on($array,$field)
{
    $ret = array();
    foreach($array as $arr)
    {
        $value_field = $arr[$field];
        $ret[$value_field][] = $arr;
    }
    return array_values($ret);
}
print_r(split_on($data,"day"));

结果：

Array
(
    [0] => Array
        (
            [action] => 1
            [day] => day_2
        )

    [1] => Array
        (
            [action] => 2
            [day] => day_1
        )

    [2] => Array
        (
            [action] => 3
            [day] => day_1
        )

    [3] => Array
        (
            [action] => 4
            [day] => day_2
        )

    [4] => Array
        (
            [action] => 5
            [day] => day_1
        )

)
Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [action] => 1
                    [day] => day_2
                )

            [1] => Array
                (
                    [action] => 4
                    [day] => day_2
                )

        )

    [1] => Array
        (
            [0] => Array
                (
                    [action] => 2
                    [day] => day_1
                )

            [1] => Array
                (
                    [action] => 3
                    [day] => day_1
                )

            [2] => Array
                (
                    [action] => 5
                    [day] => day_1
                )

        )

)