php - 如何按值对多维数组进行排序？(How to Sort Multi-dimensional Array by Value?)

Question

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

(如何按“订单”键的值对该数组排序？)

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

(即使这些值当前是连续的，也不会总是如此。)

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
        )
)

  ask by stef translate from so

Answer 1

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

(尝试使用usort ，如果您仍然使用PHP 5.2或更早版本，则必须首先定义一个排序函数：)

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

usort($myArray, 'sortByOrder');

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

(从PHP 5.3开始，您可以使用匿名函数：)

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

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

(最后，在PHP 7中，您可以使用spaceship运算符 ：)

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

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below.

(要将其扩展到多维排序，如果第二个/第三个排序元素为零，请参考第二个/第三个排序元素-下文将详细说明。)

You can also use this for sorting on sub-elements.

(您也可以使用它对子元素进行排序。)

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;
});

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

(如果需要保留键关联，请使用uasort() -请参见手册中数组排序功能的比较)