按子数组的大小对多维数组进行排序 [英] Sort a multi-dimensional array by the size of its sub-arrays

问题描述

我有这个多维数组:

Array
(
    [0] => Array
        (
        [0] => 2012-02-26 07:15:00
        )
    [1] => Array
        (
            [0] => 2012-02-26 17:45:00
            [1] => 2012-02-26 18:55:00
        )
    [2] => Array
        (
            [0] => 2012-02-26 18:55:00
            [1] => 2012-02-26 17:45:00
        )
    [3] => Array
        (
            [0] => 2012-02-26 18:57:00
            [1] => 2012-02-26 17:45:00
            [2] => 2012-02-26 18:55:00
        )

当我计算子数组时，我得到了1,2,2,3.我怎样才能在3、2、2、1中收到?例如，我需要获取具有最高子数组计数(DESC，这意味着3、2、2)的最后3个子数组.我该如何实现?

When I count subarrays I get this 1,2,2,3. How could I receive it in 3,2,2,1? I need to get for example last 3 subarrays with the highest subarray count (DESC, it means 3,2,2). How can I achieve this?

推荐答案

您可以通过使用 usort 函数来实现

You can achieve it by utilizing usort function.

function cmp($a, $b){
    return (count($b) - count($a));
}
usort($array, 'cmp');
$highest_3_sub_arrays = array_slice($array, 0, 3);

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