php - 在 PHP 中对多维数组进行排序

Question

我的数组看起来像这样:

Array
(
[0] => Array
    (
        [0] => 1
        [1] => 6
        [2] => 4
        [3] => 5
    )

[1] => Array
    (
        [0] => 272.05
        [1] => 63.54
        [2] => 544.79
        [3] => 190.62
    )

[2] => Array
    (
        [0] => 2011-03-06 14:08:19
        [1] => 2011-03-06 14:29:04
        [2] => 2011-03-06 14:28:39
        [3] => 2011-03-06 14:29:28
    )

)

我想按 $myArray[1] 排序。我有这个 usort 函数:

function sortAmount($a, $b) { 
    return strnatcmp($a[1], $b[1]); 
}

它是这样调用的:

usort($myArray, "sortAmount"); 

然而，数组在调用 usort 后并没有改变。我希望 $myArray[1] 中的数字按升序排序，并且 $myArray[0] 和 $myArray[2] 中的相应索引也随之改变。

Answer 1

我想你想要array_multisort :

array_multisort($a[1], $a[0], $a[2]);

给予

Array
(
    [0] => Array
        (
            [0] => 6
            [1] => 5
            [2] => 1
            [3] => 4
        )

    [1] => Array
        (
            [0] => 63.54
            [1] => 190.62
            [2] => 272.05
            [3] => 544.79
        )

    [2] => Array
        (
            [0] => 2011-03-06 14:29:04
            [1] => 2011-03-06 14:29:28
            [2] => 2011-03-06 14:08:19
            [3] => 2011-03-06 14:28:39
        )

)

---

除此之外，为什么要使用 strcmp 来比较数字？