php 从数组中删除重复项
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/5036403/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Remove duplicate items from an array
提问by laukok
I use the line of code below to loop through a table in my database:
我使用下面的代码行遍历数据库中的表：
$items_thread = $connection -> fetch_all($sql);
And if I print the array out:
如果我打印出数组：
print_r($items_thread);
I will get this:
我会得到这个：
Array
(
[0] => Array
(
[RecipientID] => 3
[RecipientScreenname] => Tom L
[RecipientFirstname] => Thomas
[RecipientEmail] => [email protected]
)
[1] => Array
(
[RecipientID] => 3
[RecipientScreenname] => Tom L
[RecipientFirstname] => Thomas
[RecipientEmail] => [email protected]
)
[2] => Array
(
[RecipientID] => 1
[RecipientScreenname] => Lau T
[RecipientFirstname] => TK
[RecipientEmail] => [email protected]
)
)
But I want to get rid of the duplicate items in the array, so I use array_unique
但我想摆脱数组中的重复项，所以我使用 array_unique
print_r(array_unique($items_thread));
I get the weird result below which is not quite I am looking for:
我得到以下奇怪的结果，这并不是我想要的：
Array
(
[0] => Array
(
[RecipientID] => 3
[RecipientScreenname] => Tom L
[RecipientFirstname] => Thomas
[RecipientEmail] => [email protected]
)
)
Ideally, I think it should return this:
理想情况下，我认为它应该返回：
Array
(
[0] => Array
(
[RecipientID] => 3
[RecipientScreenname] => Tom L
[RecipientFirstname] => Thomas
[RecipientEmail] => [email protected]
)
[1] => Array
(
[RecipientID] => 1
[RecipientScreenname] => Lau T
[RecipientFirstname] => TK
[RecipientEmail] => [email protected]
)
)
What shall I do to get it right? Have I used the wrong PHP syntax/default function?
我该怎么做才能做到正确？我是否使用了错误的 PHP 语法/默认函数？
回答by Tim Cooper
The array_uniquefunction will do this for you. You just needed to add the SORT_REGULARflag:
该array_unique函数将为您执行此操作。您只需要添加SORT_REGULAR标志：
$items_thread = array_unique($items_thread, SORT_REGULAR);
However, as brensuggests, you should do this in SQL if possible.
但是，正如bren 所建议的，如果可能，您应该在 SQL 中执行此操作。
回答by bren
You'd be much better off filtering out the duplicates in the SQL query. add a constraint which fetches a UNIQUE recipientID
您最好过滤掉 SQL 查询中的重复项。添加获取唯一收件人 ID 的约束
回答by bren
To remove duplicate values then we can use array_unique()function. The functionality of it is to accept an array and returns another array without duplicate values.
要删除重复值，我们可以使用array_unique()函数。它的功能是接受一个数组并返回另一个没有重复值的数组。
General description of array_unique() is given below:
array_unique() 的一般描述如下：
General Format = array array_unique(array $array [, int $sort_flags=sort_string] )
Parameters = array: Input array ->sort_flags:
The second optional parameter is used to compare items as follows
1. SORT_REGULAR - Normal
2. SORT_NUMERIC - Numerically
3. SORT_STRING - As
4. string SORT_LOCALE_STRING - As string, based on the current locale.
Return Value = Another array without duplicate values
Example 1:
示例 1：
<?php
$array=array('cricket'=>11,'football'=>11,'chess'=>2);
echo"<br/><b>Initially the values of $array is:</b><br/>";
var_dump($array);
echo"<br/><b>After removing the duplicates:</b><br/>";
print_r(array_unique($array));
?>
Output:
输出：
Initially the values of $array is:
array(3) {
["cricket"] => int(11)
["football"] => int(11)
["chess"] => int(2)
}
After removing the duplicates:
Array
(
[cricket] => 11
[chess] => 2
)
回答by Alix Axel
Try this:
尝试这个：
$data = array_map('unserialize', array_unique(array_map('serialize', $data)));
Outputs the following:
输出以下内容：
Array
(
[0] => Array
(
[RecipientID] => 3
[RecipientScreenname] => Tom L
[RecipientFirstname] => Thomas
[RecipientEmail] => [email protected]
)
[2] => Array
(
[RecipientID] => 1
[RecipientScreenname] => Lau T
[RecipientFirstname] => TK
[RecipientEmail] => [email protected]
)
)
But I also think you should implement this in your database. Also, check my other answerand solutions.
但我也认为你应该在你的数据库中实现它。另外，请检查我的其他答案和解决方案。
回答by Rajat Singh
You can use this code and I hope it will help you. It's completely working:
您可以使用此代码，希望对您有所帮助。它完全有效：
$array = array(1,1,2,3,4,4,4,5);
$temp=array();
for($i=0; $i<=count($array); $i++)
{
if($array[$i] != '')
{
for($j=$i+1; $j<=count($array); $j++ )
{
if($array[$i]==$array[$j])
{
$array[$j] = '';
}
else
{
$temp[$array[$i]]=$array[$i];
}
}
}
}
print_r($temp);
回答by H A?d?μ
$unique = array_keys(array_flip($array));
$unique = array_keys(array_flip($array));
It's is faster, plus it reset the array key index.
它更快，而且它重置了数组键索引。
source: http://php.net/manual/en/function.array-unique.php#89519
来源：http: //php.net/manual/en/function.array-unique.php#89519
This only for a simple array.
这仅适用于简单数组。
回答by Raju Dudhrejiya
Please check below code, I hope this is help full for you.
请检查下面的代码，我希望这对您有帮助。
$resultArray = uniqueAssocArray($actualArray, 'RecipientID');
function uniqueAssocArray($array, $uniqueKey) {
if (!is_array($array)) {
return array();
}
$uniqueKeys = array();
foreach ($array as $key => $item) {
$groupBy=$item[$uniqueKey];
if (isset( $uniqueKeys[$groupBy]))
{
//compare $item with $uniqueKeys[$groupBy] and decide if you
//want to use the new item
$replace= false;
}
else
{
$replace=true;
}
if ($replace) $uniqueKeys[$groupBy] = $item;
}
return $uniqueKeys;
}
}
回答by suresh kumawat
$res1 = mysql_query("SELECT * FROM `luggage` where r_bus_no='".$tour_id."' and `date1`='$date' AND `login_id`='".$_SESSION['login_id']."'");
}
/// create a array to store value
$city_arr = array();
if(mysql_num_rows($res1)>0)
{
while($row1 = mysql_fetch_array($res1))
{
/// insert the value in array use the array_push function
array_push($city_arr,$row1['r_to']);
}
//// remove the duplicate entry in array use the array_unique function
$a = array_unique($city_arr);
echo "<option value='' selected='selected'> -- Select City ---</option>";
foreach($a as $b)
{
?>
<option value="<?php echo $b ;?>"><?php echo city($b); ?></option>
<?php
}
}
回答by Byron Whitlock
You can use the regular php arrays to achieve this.
您可以使用常规的 php 数组来实现这一点。
$newArray = array();
foreach ($origArray as $user)
{
$newArray[$user['RecipientID']] = $user;
}
