按自定义顺序对数组的 php 数组进行排序 [英] Sorting a php array of arrays by custom order

问题描述

我有一个数组:

Array ( 
    [0] => Array (
        [id] = 7867867,
        [title] = 'Some Title'),
    [1] => Array (
        [id] = 3452342,
        [title] = 'Some Title'),
    [2] => Array (
        [id] = 1231233,
        [title] = 'Some Title'),
    [3] => Array (
        [id] = 5867867,
        [title] = 'Some Title')
)

需要按照特定的顺序:

1. 3452342
2. 5867867
3. 7867867
4. 1231233

我该怎么做?我之前对数组进行过排序，并阅读了很多关于它的其他文章，但它们总是基于比较(即 valueA

How would I go about doing that? I have sorted arrays before, and read plenty of other posts about it, but they are always comparison based (i.e. valueA < valueB).

感谢帮助.

推荐答案

您可以使用 usort() 来精确指定数组的排序方式.在这种情况下，可以在比较函数中使用 $order 数组.

You can use usort() to dictate precisely how the array is to be sorted. In this case, the $order array can be used within the comparison function.

下面的示例使用 closure 使生活更轻松.

The example below uses a closure to make life easier.

$order = array(3452342, 5867867, 7867867, 1231233);
$array = array(
    array('id' => 7867867, 'title' => 'Some Title'),
    array('id' => 3452342, 'title' => 'Some Title'),
    array('id' => 1231233, 'title' => 'Some Title'),
    array('id' => 5867867, 'title' => 'Some Title'),
);

usort($array, function ($a, $b) use ($order) {
    $pos_a = array_search($a['id'], $order);
    $pos_b = array_search($b['id'], $order);
    return $pos_a - $pos_b;
});

var_dump($array);

这项工作的关键是要比较值，即 $order 数组中 id 的位置.

The key to this working is having the values that are being compared, be the positions of the ids within the $order array.

比较函数的工作原理是在 $order 数组中查找要比较的两个项目的 id 的位置.如果 $a['id'] 在 $order 数组中出现在 $b['id'] 之前，则返回值function 将是负数($a 更少，因此浮动"到顶部).如果 $a['id'] 出现在 $b['id'] 之后，则该函数返回一个正数($a 大于所以下沉").

The comparison function works by finding the positions of the ids of two items to be compared within the $order array. If $a['id'] comes before $b['id'] in the $order array, then the return value of the function will be negative ($a is less so "floats" to the top). If $a['id'] comes after $b['id'] then the function returns a positive number ($a is greater so "sinks" down).

最后，使用闭包没有什么特别的理由；这只是我快速编写此类一次性函数的首选方式.它同样可以使用普通的命名函数.

Finally, there is no special reason for using a closure; it's just my go-to way of writing these sorts of throwaway functions quickly. It could equally use a normal, named function.

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