Question

我有这个数组

Array
(
[data] => Array
    (
        [0] => Array
            (

                [id] => 1293005125
                [viewed] => TRUE
                [active] => TRUE
                [time] => December 22, 2010 13:00 hours
                [timestamp] => 1293006034
                [initial_timestamp] => 1293005125
                [user] => administrator
            )

        [1] => Array
            (

                [mid] => 1293001908
                [viewed] => TRUE
                [active] => TRUE
                [time] => December 22, 2010 13:00 hours
                [timestamp] => 1293001908
                [initial_timestamp] => 1293001908
                [user] => administrator
            )

        [2] => Array
            (

                [mid] => 1293009999
                [viewed] => TRUE
                [active] => TRUE
                [time] => December 22, 2010 13:00 hours
                [timestamp] => 1293009999
                [initial_timestamp] => 1293009999
                [user] => administrator
            )

        [3] => Array
            (

                [mid] => 1293006666
                [viewed] => TRUE
                [active] => TRUE
                [time] => December 22, 2010 13:00 hours
                [timestamp] => 1293006666
                [initial_timestamp] => 1293006666
                [user] => administrator
            )

        [4] => Array
            (

                [mid] => 1293005125
                [viewed] => TRUE
                [active] => TRUE
                [time] => December 22, 2010 13:00 hours
                [timestamp] => 1293006125
                [initial_timestamp] => 1293005125
                [user] => administrator2
            )


    )

现在我想按[mid]排序这个数组我该怎么做？

目前我在foreach循环中对此进行排序必须有更好的方法

修改我希望输出像

这样的东西

[mid] key => array value

由于

Answer 1

您可以使用usort功能。

function cmp($a, $b) {
        return $a["mid"] - $b["mid"];
}
usort($arr, "cmp");

See it

Answer 2

另一种解决方案是使用array_multisort

<?php
// Obtain a list of columns
foreach ($data as $key => $row) {
    $mid[$key]  = $row['mid'];
}

// Sort the data with mid descending
// Add $data as the last parameter, to sort by the common key
array_multisort($mid, SORT_DESC, $data);
?>

Answer 3

更新

我最近在关于排序多维数组的“权威”主题中以更有能力的方式提出了这个问题answered。下面的答案针对旧版本的PHP（5.2及更早版本）;虽然这个概念是合理的，但现在有更好的做事方式。请改为阅读其他问题的答案。

原创（非常过时）回答

usort就是出于这种情况。如果您还需要保留密钥，则相应的功能为uasort。

例如：

usort($array, create_function('$a, $b',
   'if ($a["mid"] == $b["mid"]) return 0; return ($a["mid"] < $b["mid"]) ? -1 : 1;'));

当然，如果您不介意，可以正确声明比较功能：

function compareMid($a, $b)
{
    if ($a['mid'] == $b['mid']) {
        return 0;
    }
    return ($a['mid'] < $b['mid']) ? -1 : 1;
}

并像这样使用它：

usort($array, 'compareMid');

所有这些都在文档中。

按子值排序php多维数组

3 个答案:

更新

原创（非常过时）回答