php PHP按值唯一数组？
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PHP unique array by value?
提问by Jens T?rnell
I have an array in PHP that looks like this:
我在 PHP 中有一个数组，如下所示：
[0]=>
array(2) {
["name"]=>
string(9) "My_item"
["url"]=>
string(24) "http://www.my-url.com/"
}
[1]=>
array(2) {
["name"]=>
string(9) "My_item"
["url"]=>
string(24) "http://www.my-url2.com/"
}
The two values in "name" are the same in this two items. I want to sort out duplicates like this.
“name”中的两个值在这两项中是相同的。我想整理出这样的重复项。
How do I create an unique array by checking the "name" value?
如何通过检查“名称”值来创建唯一数组？
回答by user187291
basically
基本上
foreach($your_array as $element) {
$hash = $element[field-that-should-be-unique];
$unique_array[$hash] = $element;
}
回答by GordyD
Serialisationis very useful for simplifying the process of establishing the uniqueness of a hierarchical array. Use this one liner to retrieve an array containing only unique elements.
序列化对于简化建立分层数组唯一性的过程非常有用。使用这个一个 liner 来检索一个只包含唯一元素的数组。
$unique = array_map("unserialize", array_unique(array_map("serialize", $input)));
回答by Rakesh Sankar
Please find this link useful, uses md5 hash to examine the duplicates:
请发现此链接有用，使用 md5 哈希检查重复项：
http://www.phpdevblog.net/2009/01/using-array-unique-with-multidimensional-arrays.html
http://www.phpdevblog.net/2009/01/using-array-unique-with-multidimensional-arrays.html
Quick Glimpse:
快速一瞥：
/**
* Create Unique Arrays using an md5 hash
*
* @param array $array
* @return array
*/
function arrayUnique($array, $preserveKeys = false)
{
// Unique Array for return
$arrayRewrite = array();
// Array with the md5 hashes
$arrayHashes = array();
foreach($array as $key => $item) {
// Serialize the current element and create a md5 hash
$hash = md5(serialize($item));
// If the md5 didn't come up yet, add the element to
// to arrayRewrite, otherwise drop it
if (!isset($arrayHashes[$hash])) {
// Save the current element hash
$arrayHashes[$hash] = $hash;
// Add element to the unique Array
if ($preserveKeys) {
$arrayRewrite[$key] = $item;
} else {
$arrayRewrite[] = $item;
}
}
}
return $arrayRewrite;
}
$uniqueArray = arrayUnique($array);
var_dump($uniqueArray);
See the working example here: http://codepad.org/9nCJwsvg
请参阅此处的工作示例：http: //codepad.org/9nCJwsvg
回答by Kai-Tobias Bartholome
Simple Solution:
简单的解决方案：
/**
* @param $array
* @param null $key
* @return array
*/
public static function unique($array,$key = null){
if(null === $key){
return array_unique($array);
}
$keys=[];
$ret = [];
foreach($array as $elem){
$arrayKey = (is_array($elem))?$elem[$key]:$elem->$key;
if(in_array($arrayKey,$keys)){
continue;
}
$ret[] = $elem;
array_push($keys,$arrayKey);
}
return $ret;
}
回答by Медведев Александр
function unique_multidim_array($array, $key) {
$temp_array = array();
$i = 0;
$key_array = array();
foreach($array as $val) {
if (!in_array($val[$key], $key_array)) {
$key_array[$i] = $val[$key];
$temp_array[$i] = $val;
}
$i++;
}
return $temp_array;
}
$result = unique_multidim_array($visitors,'ip');
回答by symcbean
Given that the keys on the array (0,1) do not seem to be significant a simple solution would be to use the value of the element referenced by 'name' as the key for the outer array:
鉴于数组 (0,1) 上的键似乎并不重要，一个简单的解决方案是使用“name”引用的元素的值作为外部数组的键：
["My_item"]=>
array(2) {
["name"]=>
string(9) "My_item"
["url"]=>
string(24) "http://www.my-url.com/"
}
...and if there is only one value other than the 'name' why bother with a nested array at all?
...如果除了“名称”之外只有一个值，为什么还要麻烦嵌套数组呢？
["My_item"]=>"http://www.my-url.com/"
