PHP - 多uasort功能突破整理 [英] PHP - Multiple uasort functions breaks sorting

问题描述

我有一个存储人的多维数组。

I have a multidimensional array that stores people.

Array (
   id93294 => (array (
             Name => "Tom Anderson",
             Birthday => "03/17/1975"),
   id29349 => (array (
             Name => "Tom Anderson",
             Birthday => "03/17/1975")
)

有点像，除了为人民更多的信息，所以我想先排序生日再由另一个属性排序（如果他们的家乡符合其当前位置），但一旦我做了第二次排序阵列上它失去了第一类我没有使用生日...

Kind of like that except with more info for the people, so I want to first sort by birthdays THEN sort by another attribute (if their hometown matches their current location) but once I do the second sort on the array it loses the first sort I did using the birthdays...

我有点多次如何没有它搞乱了我的previous排序。

How do I sort multiple times without it messing up my previous sorts.

P.S。我使用uasort。

P.S. I am using uasort.

推荐答案

我最近<一个href=\"http://stackoverflow.com/questions/96759/how-do-i-sort-a-multidimensional-array-in-php/16788610#16788610\">answered这个问题在功能更加实用的方式，在权威主题的排序多维数组。你可以跳过阅读这个答案的其余部分，直接按照链接，一个更强大的多的解决方案。

Update

I recently answered this question in a much more capable manner in the "definitive" topic on sorting multidimensional arrays. You can safely skip reading the rest of this answer and directly follow the link for a much more capable solution.

功能 uasort ，您可以定义自己的比较函数。简单地说所有你想要的内部的标准。

The function uasort lets you define your own comparison function. Simply put all the criteria you want inside that.

例如，生日，然后按名称排序：

For example, to sort by birthday and then by name:

function comparer($first, $second) {
    // First see if birthdays differ
    if ($first['birthday'] < $second['birthday']) {
        return -1;
    }
    else if ($first['birthday'] > $second['birthday']) {
        return 1;
    }

    // OK, birthdays are equal. What else?
    if ($first['name'] < $second['name']) {
        return -1;
    }
    else if ($first['name'] > $second['name']) {
        return 1;
    }

    // No more sort criteria. The two elements are equal.
    return 0;
}

我忽略了一个事实，在你的榜样，生日不在，可以通过一个简单的对比使用操作＆LT订购的格式; 。在实践中，你会将其转换为一个平凡的，比较的格式第一。

I am ignoring the fact that in your example, the birthdays are not in a format that can be ordered by a simple comparison using the operator <. In practice you would convert them to a trivially-comparable format first.

更新：如果您认为维护一堆这些多标准comparers能拿丑陋实快，你找我同意。但是，这个问题可以在计算机科学来解决任何其他：只需添加另一个抽象级别

Update: if you think that maintaining a bunch of these multiple-criteria comparers could get ugly real fast, you find me in agreement. But this problem can be solved as any other in computer science: just add another level of abstraction.

我就假设了PHP 5.3的下一个例子，为了使用方便的匿名函数的语法。但在原则上，你可以做同样的 create_function 。

I 'll be assuming PHP 5.3 for the next example, in order to use the convenient anon function syntax. But in principle, you could do the same with create_function.

function make_comparer() {
    $criteriaNames = func_get_args();
    $comparer = function($first, $second) use ($criteriaNames) {
        // Do we have anything to compare?
        while(!empty($criteriaNames)) {
            // What will we compare now?
            $criterion = array_shift($criteriaNames);

            // Do the actual comparison
            if ($first[$criterion] < $second[$criterion]) {
                return -1;
            }
            else if ($first[$criterion] > $second[$criterion]) {
                return 1;
            }

        }

        // Nothing more to compare with, so $first == $second
        return 0;
    };

    return $comparer;
}

您可以然后执行：

uasort($myArray, make_comparer('birthday', 'name'));

这个例子可能会试图太聪明;一般我不喜欢使用不按名称接受其参数的函数。但是，在这种情况下，使用场景是太聪明了非常有力的论据。

This example possibly tries to be too clever; in general I don't like to use functions that do not accept their arguments by name. But in this case, the usage scenario is a very strong argument for being too clever.

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