如何按值对多维数组进行排序 [英] How to Sort a Multi-dimensional Array by Value

问题描述

如何根据order"的值对这个数组进行排序?关键?

How can I sort this array by the value of the "order" key?

即使这些值当前是连续的，但它们并不总是如此.

Even though the values are currently sequential, they will not always be.

Array
(
    [0] => Array
        (
            [hashtag] => a7e87329b5eab8578f4f1098a152d6f4
            [title] => Flower
            [order] => 3
        )

    [1] => Array
        (
            [hashtag] => b24ce0cd392a5b0b8dedc66c25213594
            [title] => Free
            [order] => 2
        )

    [2] => Array
        (
            [hashtag] => e7d31fc0602fb2ede144d18cdffd816b
            [title] => Ready
            [order] => 1
        )
)

推荐答案

尝试 usort.如果您仍在使用 PHP 5.2 或更早版本，则必须先定义排序函数:

Try a usort. If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:

function sortByOrder($a, $b) {
    return $a['order'] - $b['order'];
}

usort($myArray, 'sortByOrder');

从 PHP 5.3 开始，您可以使用匿名函数:

Starting in PHP 5.3, you can use an anonymous function:

usort($myArray, function($a, $b) {
    return $a['order'] - $b['order'];
});

最后，在 PHP 7 中，您可以使用 太空船运算符:

And finally with PHP 7 you can use the spaceship operator:

usort($myArray, function($a, $b) {
    return $a['order'] <=> $b['order'];
});

要将其扩展到多维排序，如果第一个排序元素为零，则引用第二个/第三个排序元素 - 最好在下面解释.您也可以使用它对子元素进行排序.

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.

usort($myArray, function($a, $b) {
    $retval = $a['order'] <=> $b['order'];
    if ($retval == 0) {
        $retval = $a['suborder'] <=> $b['suborder'];
        if ($retval == 0) {
            $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
        }
    }
    return $retval;
});

如果您需要保留关键关联，请使用 uasort() - 参见 手册中数组排序函数的比较.

If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual.

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