PHP按自定义顺序对多维数组进行排序

问题描述

如何按值对多维数组进行排序，但顺序要自定义?

How do I sort a multidimensional array by a value, but with a custom order?

多维数组将类似于:

$attribute_content[0]['term_id'] = 76;
$attribute_content[0]['content'] = "ratio";
$attribute_content[1]['term_id'] = 18;
$attribute_content[1]['content'] = "ideal condition";
$attribute_content[2]['term_id'] = 164;
$attribute_content[2]['content'] = "genotype";
$attribute_content[3]['term_id'] = 218;
$attribute_content[3]['content'] = "genetics";
$attribute_content[4]['term_id'] = 60;
$attribute_content[4]['content'] = "height";

，并且排序是根据term_id进行的，但是将是:

and the ordering is according to the term_id, but will be:

$order = array(18,164,218,60,76);

我尝试了以下代码对数组进行重新排序，但似乎是随机的:

I've tried the following codes which re-order the array, but seemingly randomly:

usort($attribute_content, function ($a, $b) use ($order) {
 $pos_a = array_search($a, $order);
 $pos_b = array_search($b, $order);
 return $pos_a - $pos_b;
});

和

$weights = array_flip($order);
usort($attribute_content, function($x, $y) use($weights) {
    return $weights[$x['term_id']] - $weights[$y['term_id']];
});

请帮助

推荐答案

您的 usort 无法正常工作，因为其中的 $ a 和 $ b 回调函数并不完全符合您的想法.它们不是'term_id'值.它们是整个内部数组，例如

Your usort is not working because $a and $b in the callback function are not quite what you think they are. They aren't 'term_id' values. They are the entire inner array, e.g.

array('term_id' => 76, 'content' => 'ratio')

因此，将它们用作 array_search 与您的 $ order 数组的参数将不起作用，因为它们不在该数组中.所有 array_search 都将返回 false ，因此看似随机.您只需要指定 term_id 键，就像这样，它将按预期工作:

So using them as an argument to array_search with your $order array won't work, because they aren't in that array. All the array_searches will just return false, hence the seemingly random sort. You just need to specify the term_id key, like this, and it will work as expected:

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

---

就您尝试的第二种方法而言，我真的不确定是什么问题.它似乎正常工作: https://3v4l.org/oJhJs

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