問題描述

---數組 $points----

Array
    (
        [0] => Array
            (
                [0] => 2011-10-02 05:30:00
                [1] => 20
            )

        [1] => Array
            (
                [0] => 2011-10-04 09:30:00
                [1] => 12
            )

        [2] => Array
            (
                [0] => 2011-10-01 13:30:00
                [1] => 25
            )

        [3] => Array
            (
                [0] => 2011-10-03 02:30:00
                [1] => 31
            )

    )

我在上面有一個數組，想按時間對這個數組進行排序.然后我使用以下代碼進行排序并且結果是正確的.但是，如果我將代碼time[$key] = $val[0] 改為$time = $val[0]，結果是錯誤的.

I have an array at above and would like to sort this array by time. Then I used the code as following to sort and result is correct. However, if I changed the code time[$key] = $val[0] to $time = $val[0], the result is wrong.

有沒有人可以向我解釋一下?非常感謝！

Is there anyone can explain this to me? Many thanks!

foreach($points as $key=>$val){

        $time[$key] = $val[0];

        array_multisort($time, SORT_ASC, $points);
    }

推薦答案

array_multisort 一次對多個數組進行排序.但是，它適用于列數組，因此需要 foreach 循環來獲取時間列.建立此列表后，您可以執行多重排序.$points 數組根據 $times 中的索引進行排序，按照 文檔中的這個例子.

array_multisort sorts more than one array at once. However, it works on an array of columns, so the foreach loop is needed to get a column of the times. After building up this list, you can then perform the multisort. The $points array is ordered according to the indices in $times, as per this example in the docs.

但是，您不需要在 foreach 中執行排序，因為這意味著排序發生了 4 次(在您的示例中).它只需要發生一次:

However, you don't need to perform the sort inside the foreach, as that means the sort happens 4 times (in your example). It only needs to happen once:

foreach ($points as $key => $val) {
    $time[$key] = $val[0];
}

array_multisort($time, SORT_ASC, $points);

這篇關于php中按時間排序數組的問題的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！