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排序[1].我有这个usort功能:

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

它被称为这样:

usort($myArray, "sortAmount"); 

但是,调用usort后,数组不会更改.我希望$ myArray [1]中的数字按升序排序,并且$ myArray [0]和$ myArray [2]中的相应索引随之改变.

Answer 1

我想你想要array_multisort:

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

给

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,你为什么strcmp要比较数字呢？