array_diff_assoc
To return the unique elements (those with a key that exists only once in either array but not in both) try:
function array_unique_diff ($array1, $array2)
{
array_merge(array_diff_key($array1, $array2), array_diff_key($array2, $array1));
}
Example:
$array1 = array('blue' => 1, 'red' => 2, 'green' => 3, 'purple' => 4);
$array2 = array('green' => 5, 'blue' => 6, 'yellow' => 7, 'cyan' => 8);
array_diff_key($array1, $array2)
returns
array ( 'red' => 2, 'purple' => 4 )
array_diff_key($array2, $array1)
returns
array ( 'yellow' => 7, 'cyan' => 8, )
array_unique_diff($array1, $array2);
returns
array ( 'red' => 2, 'purple' => 4, 'yellow' => 7, 'cyan' => 8, )
array_diff_key
(PHP 5 >= 5.1.0)
array_diff_key — Oblicza różnicę tablic używając kluczy do porównań
Opis
array array_diff_key
( array
$tablica1
, array $tablica2
[, array $ ...
] )
array_diff_key() zwraca wszystkie wartości z
tablica1, które nie są obecne w żadnym z
pozostałych argumentów. Asocjacje są zachowywane. Ta funkcja jest podobna
do array_diff(), z tym, że do porównania używane są
klucze tablicy zamiast ich wartości.
Przykład #1 Przykład użycia array_diff_key()
<?php
$tablica1 = array('niebieski' => 1, 'czerwony' => 2, 'zielony' => 3, 'purpurowy' => 4);
$tablica2 = array('zielony' => 5, 'niebieski' => 6, 'żółty' => 7, 'cyan' => 8);
var_dump(array_diff_key($tablica1, $tablica2));
?>
Powyższy przykład wyświetli:
array(2) {
["czerwony"]=>
int(2)
["purpurowy"]=>
int(4)
}
Dwa klucze z par klucz => wartość są uznawane za równe tylko jeśli (string) $klucz1 === (string) $klucz2 . Inaczej mówiąc, zachodzi ścisłe sprawdzanie, a więc reprezentacje tekstowe muszą być takie same.
Informacja: Funkcja ta sprawdza tylko jeden wymiar n-wymiarowej tablicy. Można sprawdzać głębsze wymiary przez użycie, na przykład array_diff_assoc($tablica1[0], $tablica2[0]);.
Patrz także: array_diff(), array_udiff() array_diff_assoc(), array_diff_uassoc(), array_udiff_assoc(), array_udiff_uassoc(), array_diff_ukey(), array_intersect(), array_intersect_assoc(), array_intersect_uassoc(), array_intersect_key() i array_intersect_ukey().
add a note
User Contributed Notes
array_diff_key - [15 notes]
Ashton ¶
5 years ago
division-par-zero at zilon dot net ¶
4 years ago
you can use this function for return the difference of two array !
<?php
function array_unique_diff_key ($array1, $array2)
{
if (is_array($array1) && is_array($array2))
return array_diff_key($array1, $array2) + array_diff_key($array2, $array1);
else if (is_array($array1)) return $array1;
else if (is_array($array2)) return $array2;
else return array();
}
?>
sjungwirth at matrix-consultants dot com ¶
5 years ago
I needed something a little different where maybe even the keys in multidimensional arrays don't match up. Setting $assoc to false will cause only to check for missing keys, otherwise it compares values as well. This was also based on '2ge at 2ge dot us' function
<?php
function n_array_diff_assoc ($a1, $a2, $assoc=true) {
$r = array();
if(is_array(current($a1))):
foreach($a1 as $k => $v):
if(isset($a2[$k])):
$diff = n_array_diff($a1[$k], $a2[$k], $assoc);
if (!empty($diff)):
$r[$k] = $diff;
endif;
else:
$r[$k] = $v;
endif;
endforeach;
else:
$r = $assoc ? array_diff_assoc($a1, $a2) : array_diff_key($a1, $a2);
endif;
return $r;
}
?>
AiFiLTr0 [at host] invyl [dot] ath.cx ¶
5 years ago
The recursive function suggested by '2ge at 2ge dot us' will provide you with empty arrays if there's no diff.
This variant of the function cleans up empty arrays and fixes a bug in the first suggested version. It works 100%
.
<?php
function array_diff_key_recursive ($a1, $a2) {
foreach($a1 as $k => $v) {
//$r[$k] = is_array($v) ? $this->array_diff_key_recursive($a1[$k], $a2[$k]) : array_diff_key($a1, $a2);
if (is_array($v))
{
$r[$k]=$this->array_diff_key_recursive($a1[$k], $a2[$k]);
}else
{
$r=array_diff_key($a1, $a2);
}
if (is_array($r[$k]) && count($r[$k])==0)
{
unset($r[$k]);
}
}
return $r;
}
?>
ampf at egp dot up dot pt ¶
7 years ago
Well, you could implement in the code something more powerfull:
http://www.php.net/manual/en/function.array-diff.php#31364
maxence at pontapreta dot net ¶
7 years ago
Seems to be a great function, especially for n-dimensions arrays. The only problem is that I cannot find it in php 5.0.3 and 5.0.4. Does it really exist ?! :(
[20:27:05][maxence@conurb] ~/test2/php-5.0.4$ grep PHP_FUNCTION * -r | grep -i array_diff_key
[20:27:09][maxence@conurb] ~/test2/php-5.0.4$
2ge at 2ge dot us ¶
7 years ago
Hello, if you need diff key of n-dimensional arrays here is nice solution:
<?php
function n_array_diff ($a1, $a2) {
foreach($a1 as $k => $v) {
$r[$k] = is_array($v) ? n_array_diff($a1[$k], $a2[$k]) : array_diff_key($a1, $a2);
}
return $r;
}
?>
it will print everything, what is missing in $a2.
coder at gs dot com ¶
5 years ago
The PHP4 version below works only unidirectionally. If you switch the arrays around i.e. (ar2, ar1) you get different results than (ar1, ar2).
ml at iceni dot pl ¶
7 years ago
You may obtain this function with PEAR Package PHP_Compat (http://pear.php.net/package/PHP_Compat)
Then using such code is quite useful
<?php
if(!function_exists('array_diff_key')){
require_once 'PHP/Compat/Function/array_diff_key.php';
}
?>
vlad_mustafin at ukr dot net ¶
7 years ago
One more alternative variant :)
<?
if (!function_exists('array_diff_key')) {
function array_diff_key() {
$argCount = func_num_args();
$diff_arg_prefix = 'diffArg';
$diff_arg_names = array();
for ($i=0; $i < $argCount; $i++) {
$diff_arg_names[$i] = 'diffArg'.$i;
$$diff_arg_names[$i] = array_keys((array)func_get_arg($i));
}
$diffArrString = '';
if (!empty($diff_arg_names)) $diffArrString = '$'.implode(', $', $diff_arg_names);
eval("\$result = array_diff(".$diffArrString.");");
return $result;
}
}
?>
denis noessler ¶
8 years ago
if (!function_exists('array_diff_key'))
{
/**
* Computes the difference of arrays using keys for comparison
*
* @param array $valuesBase Base elements for comparison, associative
* @param array $valuesComp[,..] Comparison elements, associative
*
* @param array Elements, not existing in comparison element, associative
*/
function array_diff_key()
{
$argCount = func_num_args();
$argValues = func_get_args();
$valuesDiff = array();
if ($argCount < 2)
{
return false;
}
foreach ($argValues as $argParam)
{
if (!is_array($argParam))
{
return false;
}
}
foreach ($argValues[0] as $valueKey => $valueData)
{
for ($i = 1; $i < $argCount; $i++)
{
if (isset($argValues[$i][$valueKey]))
{
continue 2;
}
}
$valuesDiff[$valueKey] = $valueData;
}
return $valuesDiff;
}
}
y-evt at ya dot ru ¶
11 months ago
else one recursive variation.
<?php
$a = ['one' => 0, 'two' => ['y' => 0, 'x' => ['e' => 0, 'a' => 0]]];
$b = ['one' => 0, 'two' => ['y' => 0, 'x' => ['e' => 0, 'g' => 0]]];
function array_diff_key_recursive($a1, $a2) {
if (is_array($a2)) {
$r = array_diff_key($a1, $a2);
}
else {
return $a1;
}
foreach($a1 as $k => $v) {
if (is_array($v)) {
$r[$k] = array_diff_key_recursive($a1[$k], $a2[$k]);
if (is_array($r[$k]) && count($r[$k])==0) unset($r[$k]);
}
}
return $r;
}
?>
contact at autonoma dot fr ¶
5 years ago
after kwutzke's comment , here is a PHP4 array_diff_key fonction for those in need
function PHP4_array_diff_key()
{
$arrs = func_get_args();
$result = array_shift($arrs);
foreach ($arrs as $array) {
foreach ($result as $key => $v) {
if (array_key_exists($key, $array)) {
unset($result[$key]);
}
}
}
return $result;
}
works for me, enjoy.
kwutzke @ somewhere in the net ¶
6 years ago
PHP4 array_diff_key can be copied from the array_intersect_key implementation posted by some anonymous user on 2006-07-17. The only thing you have to do is to delete the '!' in the if and rename the function.
eric dot broersma at phil dot uu dot nl ¶
8 years ago
<?php
function array_diff_key()
{
$args = func_get_args();
return array_flip(call_user_func_array('array_diff',
array_map('array_flip',$args)));
}
?>