php 获取数组中重复值的键
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Get the keys for duplicate values in an array
提问by schaitanya
I have the following array:
我有以下数组：
$myarray = Array("2011-06-21", "2011-06-22", "2011-06-22", "2011-06-23", "2011-06-23", "2011-06-24", "2011-06-24", "2011-06-25", "2011-06-25", "2011-06-26");
var_dump($myarray);
Result:
结果：
Array (
[0] => 2011-06-21
[1] => 2011-06-22
[2] => 2011-06-22
[3] => 2011-06-23
[4] => 2011-06-23
[5] => 2011-06-24
[6] => 2011-06-24
[7] => 2011-06-25
[8] => 2011-06-25
[9] => 2011-06-26
)
- Now how can I display the keys with duplicate values? Here the function should NOT return ([0],[9]) since there are no duplicates with the values.
- How to find the keys for the same value, eg. for "2011-06-25" it should return [7],[8]
- 现在如何显示具有重复值的键？这里函数不应该返回 ([0],[9]) 因为没有重复的值。
- 如何找到相同值的键，例如。对于“2011-06-25”，它应该返回 [7],[8]
回答by Trey
function get_keys_for_duplicate_values($my_arr, $clean = false) {
if ($clean) {
return array_unique($my_arr);
}
$dups = $new_arr = array();
foreach ($my_arr as $key => $val) {
if (!isset($new_arr[$val])) {
$new_arr[$val] = $key;
} else {
if (isset($dups[$val])) {
$dups[$val][] = $key;
} else {
$dups[$val] = array($key);
// Comment out the previous line, and uncomment the following line to
// include the initial key in the dups array.
// $dups[$val] = array($new_arr[$val], $key);
}
}
}
return $dups;
}
obviously the function name is a bit long;)
显然函数名有点长；）
Now $dups will contain a multidimensional array keyed by the duplicate value, containing each key that was a duplicate, and if you send "true" as your second argument it will return the original array without the duplicate values.
现在 $dups 将包含一个由重复值键控的多维数组，其中包含每个重复的键，如果您发送“true”作为第二个参数，它将返回没有重复值的原始数组。
Alternately you could pass the original array as a reference and it would adjust it accordingly while returning your duplicate array
或者，您可以将原始数组作为参考传递，它会在返回重复数组时相应地调整它
回答by Francois Deschenes
I'll answer the second question first. You want to use array_keyswith the "search_value" specified.
我先回答第二个问题。您想array_keys与指定的“search_value”一起使用。
$keys = array_keys($array, "2011-06-29")
In the example below, $duplicateswill contain the duplication values while $resultwill contain ones that are not duplicates. To get the keys, simply use array_keys.
在下面的示例中，$duplicates将包含重复值，而$result将包含非重复值。要获取密钥，只需使用array_keys.
<?php
$array = array(
'a',
'a',
'b',
'c',
'd'
);
// Unique values
$unique = array_unique($array);
// Duplicates
$duplicates = array_diff_assoc($array, $unique);
// Unique values
$result = array_diff($unique, $duplicates);
// Get the unique keys
$unique_keys = array_keys($result);
// Get duplicate keys
$duplicate_keys = array_keys(array_intersect($array, $duplicates));
Result:
结果：
// $duplicates
Array
(
[1] => a
)
// $result
Array
(
[2] => b
[3] => c
[4] => d
)
// $unique_keys
Array
(
[0] => 2
[1] => 3
[2] => 4
)
// $duplicate_keys
Array
(
[0] => 0
[1] => 1
)
回答by Divey
I had a similar problem as question #1 from the OP. All I needed were the keys for duplicate values in my original array. Here's what I came up with:
我遇到了与 OP 中的问题 #1 类似的问题。我所需要的只是原始数组中重复值的键。这是我想出的：
$array = array('yellow', 'red', 'green', 'brown', 'red', 'brown');
$counts = array_count_values($array);
$filtered = array_filter($counts, function($value) {
return $value != 1;
});
$result = array_keys(array_intersect($array, array_keys($filtered)));
And for the output:
对于输出：
print_r($result);
Array
(
[0] => 1
[1] => 3
[2] => 4
[3] => 5
)
回答by Sandeep Panesar
function getDuplicateValueKeys($my_arr, $clean = false)
{
if ($clean) {
return array_unique($my_arr);
}
$dups = array();
$new_arr = array();
$dup_vals = array();
foreach ($my_arr as $key => $value) {
if (!isset($new_arr[$value])) {
$new_arr[$value] = $key;
} else {
array_push($dup_vals,$value);
}
}
foreach ($my_arr as $key => $value) {
if (in_array($value, $dup_vals)) {
if (!isset($dups[$value])) {
$dups[$value]=array($key);
}else{
array_push($dups[$value],$key);
}
}
}
return $dups;
}
回答by hakre
I really like Francois answer, here is something I came up with that preserves keys. I'll answer the first question first:
我真的很喜欢弗朗索瓦的回答，这是我想出的可以保留钥匙的东西。我先回答第一个问题：
$array = array('2011-06-21', '2011-06-22', '2011-06-22');
/**
* flip an array like array_flip but
* preserving multiple keys per an array value
*
* @param array $a
* @return array
*/
function array_flip_multiple(array $a) {
$result = array();
foreach($a as $k=>$v)
$result[$v][]=$k
;
return $result;
}
$hash = array_flip_multiple($array);
// filter $hash based on your specs (2 or more)
$hash = array_filter($hash, function($items) {return count($items) > 1;});
// get all remaining keys
$keys = array_reduce($hash, 'array_merge', array());
var_dump($array, $hash, $keys);
output is:
输出是：
# original array
array(3) {
[0]=>
string(10) "2011-06-21"
[1]=>
string(10) "2011-06-22"
[2]=>
string(10) "2011-06-22"
}
# hash (filtered)
array(1) {
["2011-06-22"]=>
array(2) {
[0]=>
int(1)
[1]=>
int(2)
}
}
# the keys
array(2) {
[0]=>
int(1)
[1]=>
int(2)
}
So now the second question:
那么现在第二个问题：
Just use the $hashto obtain the keys for the value:
只需使用$hash来获取值的键：
var_dump($hash['2011-06-22']);returns the keys.
var_dump($hash['2011-06-22']);返回密钥。
Benefit is, if you need to check multiple values, data is already stored in the hash and available for use.
好处是，如果您需要检查多个值，数据已经存储在哈希中并可供使用。
回答by Dogbert
$array = array(0 => "1", 1 => "1", 2 => "2", 3 => "3");
$count = array();
foreach($array as $key => $value) {
if(!isset($count[$value])) {
$count[$value] = 0;
}
$count[$value]++;
}
$result = array_filter($count, function($value) {
return $value > 1;
});
$result = array_keys($result);
var_dump($result);
Output
输出
array(1) {
[0]=>
int(1)
}
回答by darkylmnx
here is a code dude
这是一个代码老兄
$your_array = array(0 => '2011-06-21', 1 => '2011-06-22', 2 => '2011-06-22', 3 => '2011-06-23', 4 =>
'2011-06-23', 5 => '2011-06-24', 6 => '2011-06-24', 7 => '2011-06-25', 8 => '2011-06-25', 9
=> '2011-06-26', 10 => '2011-06-26', 11 => '2011-06-27', 12 => '2011-06-27', 13 => '2011-06-
28', 14 => '2011-06-29', 15 => '2011-06-29', 16 => '2011-06-30', 17 => '2011-06-30', 18 =>
'2011-07-01', 19 => '2011-07-01', 20 => '2011-07-02', 21 => '2011-07-02', 22 => '2011-07-03',
23 => '2011-07-03', 24 => '2011-07-04', 25 => '2011-07-04', 26 => '2011-07-05', 27 => '2011-
07-05', 28 => '2011-07-06', 29 => '2011-07-06', 30 => '2011-07-07', 31 => '2011-07-07');
$keys_of_duplicated = array();
$array_keys = array();
foreach($your_array as $key => $value) {
//- get the keys of the actual value
$array_keys = array_keys($your_array, $value);
//- if there is more then one key collected we register it
if(count($array_keys) > 1) {
//- foreach key that have the same value we check if i'ts already registered
foreach($array_keys as $key_registered) {
//- if not registered we register it
if(!in_array($key_registered, $keys_of_duplicated)) {
$keys_of_duplicated[] = $key_registered;
}
}
}
}
var_dump($keys_of_duplicated);
$keys_of_duplicated is now the array that contains the keys of duplicated arrays ;) bye
$keys_of_duplicated 现在是包含重复数组键的数组；) 再见
回答by Dereleased
$array = array(
'2011-06-21','2011-06-22','2011-06-22','2011-06-23',
'2011-06-23','2011-06-24','2011-06-24','2011-06-25',
'2011-06-25','2011-06-26','2011-06-26','2011-06-27',
'2011-06-27','2011-06-28','2011-06-29','2011-06-29',
'2011-06-30','2011-06-30','2011-07-01','2011-07-01',
'2011-07-02','2011-07-02','2011-07-03','2011-07-03',
'2011-07-04','2011-07-04','2011-07-05','2011-07-05',
'2011-07-06','2011-07-06','2011-07-07','2011-07-07',
);
function getDupKeys(array $array, $return_first = true, $return_by_key = true) {
$seen = array();
$dups = array();
foreach ($array as $k => $v) {
$vk = $return_by_key ? $v : 0;
if (!array_key_exists($v, $seen)) {
$seen[$v] = $k;
continue;
}
if ($return_first && !array_key_exists($v, $dups)) {
$dups[$vk][] = $seen[$v];
}
$dups[$vk][] = $k;
}
return $return_by_key ? $dups : $dups[0];
}
If both optional parameters are true, it returns an array of arrays; the key of each child array will be the value which was not unique, and the values of the array will be all those keys which had that value.
如果两个可选参数都为真，则返回一个数组数组；每个子数组的键将是不唯一的值，数组的值将是所有具有该值的键。
If the first optional parameter is false, then only keys afterthe first instance of a non-unique value will be returned (i.e., for the given array, each value returns only one key, the second time it occurred, instead of the first).
如果第一个可选参数为 false，则仅返回非唯一值的第一个实例之后的键（即，对于给定的数组，每个值仅返回一个键，第二次出现，而不是第一次） .
If the second parameter is optional, then instead of returning an array of arrays, it returns a flat array containing all duplicate keys (exactly which keys it returns are dictated by the prior optional parameter).
如果第二个参数是可选的，那么它不是返回一个数组数组，而是返回一个包含所有重复键的平面数组（它返回的确切键由前一个可选参数决定）。
Here's a dumpprint_r, cause it's prettier:
这是一个转储print_r，因为它更漂亮：
print_r(getDupKeys($array));
Array
(
[2011-06-22] => Array
(
[0] => 1
[1] => 2
)
[2011-06-23] => Array
(
[0] => 3
[1] => 4
)
[2011-06-24] => Array
(
[0] => 5
[1] => 6
)
[2011-06-25] => Array
(
[0] => 7
[1] => 8
)
[2011-06-26] => Array
(
[0] => 9
[1] => 10
)
[2011-06-27] => Array
(
[0] => 11
[1] => 12
)
[2011-06-29] => Array
(
[0] => 14
[1] => 15
)
[2011-06-30] => Array
(
[0] => 16
[1] => 17
)
[2011-07-01] => Array
(
[0] => 18
[1] => 19
)
[2011-07-02] => Array
(
[0] => 20
[1] => 21
)
[2011-07-03] => Array
(
[0] => 22
[1] => 23
)
[2011-07-04] => Array
(
[0] => 24
[1] => 25
)
[2011-07-05] => Array
(
[0] => 26
[1] => 27
)
[2011-07-06] => Array
(
[0] => 28
[1] => 29
)
[2011-07-07] => Array
(
[0] => 30
[1] => 31
)
)
print_r(getDupKeys($array, false));
Array
(
[2011-06-22] => Array
(
[0] => 2
)
[2011-06-23] => Array
(
[0] => 4
)
[2011-06-24] => Array
(
[0] => 6
)
[2011-06-25] => Array
(
[0] => 8
)
[2011-06-26] => Array
(
[0] => 10
)
[2011-06-27] => Array
(
[0] => 12
)
[2011-06-29] => Array
(
[0] => 15
)
[2011-06-30] => Array
(
[0] => 17
)
[2011-07-01] => Array
(
[0] => 19
)
[2011-07-02] => Array
(
[0] => 21
)
[2011-07-03] => Array
(
[0] => 23
)
[2011-07-04] => Array
(
[0] => 25
)
[2011-07-05] => Array
(
[0] => 27
)
[2011-07-06] => Array
(
[0] => 29
)
[2011-07-07] => Array
(
[0] => 31
)
)
print_r(getDupKeys($array, true, false));
Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => 5
[5] => 6
[6] => 7
[7] => 8
[8] => 9
[9] => 10
[10] => 11
[11] => 12
[12] => 14
[13] => 15
[14] => 16
[15] => 17
[16] => 18
[17] => 19
[18] => 20
[19] => 21
[20] => 22
[21] => 23
[22] => 24
[23] => 25
[24] => 26
[25] => 27
[26] => 28
[27] => 29
[28] => 30
[29] => 31
)
print_r(getDupKeys($array, false, false));
Array
(
[0] => 2
[1] => 4
[2] => 6
[3] => 8
[4] => 10
[5] => 12
[6] => 15
[7] => 17
[8] => 19
[9] => 21
[10] => 23
[11] => 25
[12] => 27
[13] => 29
[14] => 31
)
回答by Thamisetty Krishna Mohan
Another example:
另一个例子：
$array = array(
'a',
'a',
'b',
'b',
'b'
);
echo '<br/>Array: ';
print_r($array);
// Unique values
$unique = array_unique($array);
echo '<br/>Unique Values: ';
print_r($unique);
// Duplicates
$duplicates = array_diff_assoc($array, $unique);
echo '<br/>Duplicates: ';
print_r($duplicates);
// Get duplicate keys
$duplicate_values = array_values(array_intersect($array, $duplicates));
echo '<br/>duplicate values: ';
print_r($duplicate_values);
Output:
输出：
Array :Array ( [0] => a [1] => a [2] => b [3] => b [4] => b )
Unique Values :Array ( [0] => a [2] => b )
Duplicates :Array ( [1] => a [3] => b [4] => b )
Duplicate Values :Array ( [0] => a [1] => a [2] => b [3] => b [4] => b )
