我如何使用array_unique数组的数组吗？ [英] How do I use array_unique on an array of arrays?

问题描述

我有一个数组

Array(
[0] => Array
    (
        [0] => 33
        [user_id] => 33
        [1] => 3
        [frame_id] => 3
    )

[1] => Array
    (
        [0] => 33
        [user_id] => 33
        [1] => 3
        [frame_id] => 3
    )

[2] => Array
    (
        [0] => 33
        [user_id] => 33
        [1] => 8
        [frame_id] => 8
    )

[3] => Array
    (
        [0] => 33
        [user_id] => 33
        [1] => 3
        [frame_id] => 3
    )

[4] => Array
    (
        [0] => 33
        [user_id] => 33
        [1] => 3
        [frame_id] => 3
    )

）

正如你所看到0键是一样的1,3和4和关键2是从他们完全不同。

As you can see key 0 is the same as 1,3 and 4. And key 2 is different from them all.

在运行对他们的array_unique功能，唯一留下的就是

When running the array_unique function on them, the only left is

Array (
[0] => Array
    (
        [0] => 33
        [user_id] => 33
        [1] => 3
        [frame_id] => 3
    )

）

为什么预期array_unique不工作任何想法？

any ideas why array_unique isn't working as expected?

推荐答案

这是因为 array_unique 比较使用字符串比较的项目。从文档：

It's because array_unique compares items using a string comparison. From the docs:

注：有两个因素被认为是
  等于当且仅当（字符串）$ elem1
  ===（字符串）$ elem2时。在话：当字符串重新presentation是一样的。
  第一元件将被使用。

Note: Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is the same. The first element will be used.

再数组的presentation的字符串是简单的字阵列，不管其内容。

The string representation of an array is simply the word Array, no matter what its contents are.

您可以做你想做的事通过以下内容：

You can do what you want to do by using the following:

$arr = array(
    array('user_id' => 33, 'frame_id' => 3),
    array('user_id' => 33, 'frame_id' => 3),
    array('user_id' => 33, 'frame_id' => 8)
);

$arr = array_intersect_key($arr, array_unique(array_map('serialize', $arr)));

//result:
array
  0 => 
    array
      'user_id' => int 33
      'user' => int 3
  2 => 
    array
      'user_id' => int 33
      'user' => int 8

下面是它如何工作的：

1. 每个阵列产品系列化。这个
   基于阵列的将是唯一的
   内容。

1. Each array item is serialized. This will be unique based on the array's contents.

这样做的结果是通过 array_unique 运行，
所以只有阵列具有独特的
签名离开了。

The results of this are run through array_unique, so only arrays with unique signatures are left.

array_intersect_key 将采取
独特的项目从钥匙
图/独特的功能（自源数组的键是preserved）和拉
他们出原始源的
数组。

array_intersect_key will take the keys of the unique items from the map/unique function (since the source array's keys are preserved) and pull them out of your original source array.

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