(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
array_diff_assoc — Computes the difference of arrays with additional index check
Parametersarray
The array to compare from
arrays
Arrays to compare against
Returns an array containing all the values from array that are not present in any of the other arrays.
Example #1 array_diff_assoc() example
In this example the "a" => "green" pair is present in both arrays and thus it is not in the output from the function. Unlike this, the pair 0 => "red" is in the output because the key of "red" is automatically assigned to 0 in the first array, whereas it is assigned to 1 in the second array as the key 0 is already taken by yellow.
<?php
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "green", "yellow", "red");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
The above example will output:
Array
(
[b] => brown
[c] => blue
[0] => red
)
Example #2 array_diff_assoc() example
Two values from key => value pairs are considered equal only if (string) $elem1 === (string) $elem2 . In other words a strict check takes place so the string representations must be the same.
<?php
$array1 = array(0, 1, 2);
$array2 = array("00", "01", "2");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
The above example will output:
Array
(
[0] => 0
[1] => 1
) Notes
Note: This function only checks one dimension of an n-dimensional array. It is possible to check deeper dimensions by using, for example,
array_diff_assoc($array1[0], $array2[0]);.
See AlsoNote: Ensure arguments are passed in the correct order when comparing similar arrays with more keys. The new array should be the first in the list.
12 years ago
The array_diff_assoc_array from "chinello at gmail dot com" (and others) will not work for arrays with null values. That's because !isset is true when an array key doesn't exists or is set to null.
(sorry for the changed indent-style)
<?php
function array_diff_assoc_recursive($array1, $array2) {
$difference=array();
foreach($array1 as $key => $value) {
if( is_array($value) ) {
if( !isset($array2[$key]) || !is_array($array2[$key]) ) {
$difference[$key] = $value;
} else {
$new_diff = array_diff_assoc_recursive($value, $array2[$key]);
if( !empty($new_diff) )
$difference[$key] = $new_diff;
}
} else if( !array_key_exists($key,$array2) || $array2[$key] !== $value ) {
$difference[$key] = $value;
}
}
return $difference;
}
?>
And here an example (note index 'b' in the output):
<?php
$a1=array( 'a' => 0, 'b' => null, 'c' => array( 'd' => null ) );
$a2=array( 'a' => 0, 'b' => null );var_dump( array_diff_assoc_recursive( $a1, $a2 ) );
var_dump( chinello_array_diff_assoc_recursive( $a1, $a2 ) );
?>
array(1) {
["c"]=>
array(1) {
["d"]=>
NULL
}
}
array(2) {
["b"]=>
NULL
["c"]=>
array(1) {
["d"]=>
NULL
}
} telefoontoestel at hotmail dot com ¶
11 years ago
an earlier post for recursive array_diff_assoc failed because isset returned false on an array element containing a null value. I updated the code so it compares null values too.
<?php
function array_diff_assoc_recursive($array1, $array2)
{
foreach($array1 as $key => $value)
{
if(is_array($value))
{
if(!isset($array2[$key]))
{
$difference[$key] = $value;
}
elseif(!is_array($array2[$key]))
{
$difference[$key] = $value;
}
else
{
$new_diff = array_diff_assoc_recursive($value, $array2[$key]);
if($new_diff != FALSE)
{
$difference[$key] = $new_diff;
}
}
}
elseif(!array_key_exists($key, $array2) || $array2[$key] != $value)
{
$difference[$key] = $value;
}
}
return !isset($difference) ? 0 : $difference;
}
?>
Michael Richey ¶
12 years ago
If you're looking for a true array_diff_assoc, comparing arrays to determine the difference between two, finding missing values from both, you can use this along with array_merge.
$a = array('a'=>1,'b'=>2,'c'=>3);
$b = array('a'=>1,'b'=>2,'d'=>4);
print_r(array_diff_assoc($a,$b));
// returns:
array
(
[c] => 3
)
print_r(array_diff_assoc($b,$a));
// returns
array
(
[d] => 4
)
print_r(array_merge(array_diff_assoc($a,$b),array_diff_assoc($b,$a)));
// returns
array
(
[c] => 3
[d] => 4
) contact at pascalopitz dot com ¶
18 years ago
The direction of the arguments does actually make a difference:
<?php
$a = array(
'x' => 'x',
'y' => 'y',
'z' => 'z',
't' => 't',
); $b = array(
'x' => 'x',
'y' => 'y',
'z' => 'z',
't' => 't',
'g' => 'g',
); print_r(array_diff_assoc($a, $b));
print_r(array_diff_assoc($b, $a));
?>
echoes:
Array
(
)
Array
(
[g] => g
) chinello at gmail dot com ¶
18 years ago
The following will recursively do an array_diff_assoc, which will calculate differences on a multi-dimensional level. This not display any notices if a key don't exist and if error_reporting is set to E_ALL:
<?php
function array_diff_assoc_recursive($array1, $array2)
{
foreach($array1 as $key => $value)
{
if(is_array($value))
{
if(!isset($array2[$key]))
{
$difference[$key] = $value;
}
elseif(!is_array($array2[$key]))
{
$difference[$key] = $value;
}
else
{
$new_diff = array_diff_assoc_recursive($value, $array2[$key]);
if($new_diff != FALSE)
{
$difference[$key] = $new_diff;
}
}
}
elseif(!isset($array2[$key]) || $array2[$key] != $value)
{
$difference[$key] = $value;
}
}
return !isset($difference) ? 0 : $difference;
}
?>
[NOTE BY danbrown AT php DOT net: This is a combination of efforts from previous notes deleted. Contributors included (Michael Johnson), (jochem AT iamjochem DAWT com), (sc1n AT yahoo DOT com), and (anders DOT carlsson AT mds DOT mdh DOT se).] dev5er6 at gmail dot com ¶
11 years ago
Works more like the original function:
<?phpfunction array_diff_assoc_recursive ( )
{
$args = func_get_args ( );
$diff = array ( );
foreach ( array_shift ( $args ) as $key => $val )
{
for ( $i = 0, $j = 0, $tmp = array ( $val ) , $count = count ( $args ); $i < $count; $i++ )
if ( is_array ( $val ) )
if ( !isset ( $args[$i][$key] ) || !is_array ( $args[$i][$key] ) || empty( $args[$i][$key] ) )
$j++;
else
$tmp[] = $args[$i][$key];
elseif ( ! array_key_exists ( $key, $args[$i] ) || $args[$i][$key] !== $val )
$j++;
if ( is_array ( $val ) )
{
$tmp = call_user_func_array ( __FUNCTION__, $tmp );
if ( ! empty ( $tmp ) ) $diff[$key] = $tmp;
elseif ( $j == $count ) $diff[$key] = $val;
}
elseif ( $j == $count && $count ) $diff[$key] = $val;
}
return
$diff;
}?>
benjamin at moonfactory dot co dot jp ¶
20 years ago
Hi all,
For php versions < 4.3...
<?php
if (!function_exists('array_diff_assoc'))
{
function array_diff_assoc($a1, $a2)
{
foreach($a1 as $key => $value)
{
if(isset($a2[$key]))
{
if((string) $value !== (string) $a2[$key])
{
$r[$key] = $value;
}
}else
{
$r[$key] = $value;
}
}
return $r ;
}
} ?>
Alexander Podgorny ¶
19 years ago
NOTE: the diff_array also removes all the duplicate values that match to the values in the second array:
<?php
$array1 = array("a","b","c","a","a");
$array2 = array("a"); $diff = array_diff($array1,$array2); ?>
carl at thep dot lu dot se ¶
22 years ago
To unset elements in an array if you know the keys but not the values, you can do:
<?php
$a = array("foo", "bar", "baz", "quux");
$b = array(1, 3); foreach($b as $e)
unset($a[$e]);
?>
Of course this makes most sense if $b has many elements or is dynamically generated. news_yodpeirs at thoftware dot de ¶
14 years ago
A quite simple (yet not very efficient) way to compare the first level of arrays which have values that are not strings:
array_map('unserialize',array_diff_assoc(array_map('serialize',$arr1),array_map('serialize',$arr2)))
Might be useful for debugging (that's what I use it for).
16 years ago
array_diff_assoc can also be used to find the duplicates in an array
<?php
$arr = array('1','2','3','4','3','2','5');
$uniques = array_unique($arr);
$dups = array_diff_assoc($arr, $uniques); print_r($dups);
?>
Note: The index of the $dups is not in strict sequential order as expected by C programmer. cedric at daneel dot net ¶
18 years ago
To diff between n-dimensional array, juste use this :
<?php
function array_diff_values($tab1, $tab2)
{
$result = array();
foreach($tab1 as $values) if(! in_array($values, $tab2)) $result[] = $values;
return $result;
}
?>
spark dot crz at gmail dot com ¶
7 years ago
Recursive implementation accepting multiple n-level-arrays as parameters:
<?php
function recursiveDiff() {
$arrs = func_get_args();
$first = array_shift($arrs);
$diff = [];
foreach(
$first as $key => $value) {
$values = array_map(function($arr) use($key){
if (is_array($arr) && !array_key_exists($key, $arr))
return null;
return
$arr[$key];
}, $arrs);
if (
in_array($value, $values))
continue;
if (
is_array($value)) {
array_unshift($values, $value);
$diff[$key] = call_user_func_array(__FUNCTION__, $values);
continue;
}$diff[$key] = $first[$key];
}
return
$diff;
}
?>
The other attempt was cleaner but didn't work for all cases. angujomondi at gmail dot com ¶
4 years ago
For recursive diff of multiple arrays, exending solution provided by Gosh.
<?php function array_diff_assoc_recursive(array $array, array ...$arrays)
{
$func = function($array1, $array2) use (&$func){
$difference = [];
foreach ($array1 as $key => $value) {
if (is_array($value)) {
if (!isset($array2[$key]) || !is_array($array2[$key])) {
$difference[$key] = $value;
} else {
$new_diff = $func($value, $array2[$key]);
if (!empty($new_diff)) {
$difference[$key] = $new_diff;
}
}
} else {
if (!array_key_exists($key, $array2) || $array2[$key] !== $value) {
$difference[$key] = $value;
}
}
}
return $difference;
};
$diffs = $array;
foreach ($arrays as $_array) {
$diffs = $func($diffs, $_array);
}
return $diffs;
}?>
Henry ¶
1 year ago
function array_diff_assoc_recursive($array1, $array2)
{
$array1Array = [];
foreach ($array1 as $key => $value) {
if (!is_array($value)) {
continue;
}
$array1Array[$key] = $value;
unset($array1[$key]);
}
$array2Array = [];
foreach ($array2 as $key => $value) {
if (!is_array($value)) {
continue;
}
$array2Array[$key] = $value;
unset($array2[$key]);
}
$diff = is_int(array_key_first($array1)) ? array_values(array_diff($array1, $array2)) : array_diff_assoc($array1, $array2);
foreach ($array1Array as $key => $value) {
if (isset($array2Array[$key])) {
$subDiff = array_diff_assoc_recursive($value, $array2Array[$key]);
if (count($subDiff) !== 0) {
$diff = array_merge($diff, is_int($key) ? [$subDiff] : [$key => $subDiff]);
}
} else {
$diff = array_merge($diff, is_int($key) ? [$value] : [$key => $value]);
}
}
return $diff;
} folurinyinka at gmail dot com ¶
3 years ago
Recursive implementation accepting multiple n-level-arrays as parameters:
```php
function recursiveDiff(...$arrays)
{
$first = array_shift($arrays);
$diff = [];
foreach ($first as $key => $value) {
$values = array_map(function ($arr) use ($key) {
if (is_array($arr) && !array_key_exists($key, $arr)) {
return null;
}
return isset($arr[$key]) ? $arr[$key] : null;
}, $arrs);
if (in_array($value, $values)) {
continue;
}
if (is_array($value)) {
array_unshift($values, $value);
$diff[$key] = call_user_func_array(__FUNCTION__, $values);
continue;
}
$diff[$key] = $first[$key];
}
return $diff;
}
``` nekto ¶
3 years ago
PHP associative keys are case-sensitive, key "a" is different from key "A":
<?php
$arr = ["A" => 666];
var_dump($arr["a"]);
var_dump($arr["A"]);
?>
produces:
NULL
int(666)
And in the same way, array_diff_assoc treats keys case-sensitively, and key "A" is not equal to key "a" and will be diffed:
<?php
$compareWhat = ["a" => 666, "b" => 666, "c" => 666, ];
$compareWith = ["A" => 666, "b" => 667, "c" => 666, ];var_dump(array_diff_assoc($compareWhat, $compareWith));
?>
produces:
array(2) {
["a"]=> int(666)
["b"]=> int(666)
}
And if the order of values in array is different, the order of the result will be different, although essentially the result stays the same:
<?php
$compareWhat = ["b" => 666, "a" => 666, "c" => 666, ];
$compareWith = ["A" => 666, "b" => 667, "c" => 666, ];var_dump(array_diff_assoc($compareWhat, $compareWith));
?>
produces:
array(2) {
["b"]=> int(666)
["a"]=> int(666)
} shadow_games at abv dot bg ¶
11 years ago
there is a functiont that i searched long enough now i have created it so someone else to find it if he need it ;]
<?php
function compare_two_object_recursive($object_1, $object_2, $object_1_Identifier = false, $object_2_Identifier = false){
$object1 = (array)$object_1;
$object2 = (array)$object_2;
$object3 = array();$o1i = $object_1_Identifier ? $object_1_Identifier : 1;
$o2i = $object_2_Identifier ? $object_2_Identifier : 2;
foreach(
$object1 as $key => $value){
if(is_object($object1[$key])){
$object1[$key] = (array)$object1[$key];
$object2[$key] = (array)$object2[$key];
$object3[$key] = (object)compare_two_object_recursive($object1[$key], $object2[$key], $o1i, $o2i);
}elseif(is_array($object1[$key])){
$object3[$key] = compare_two_object_recursive($object1[$key], $object2[$key], $o1i, $o2i);
}else{
if($object1[$key] == $object2[$key]){
$object3[$key]['comparison_status'] = "SAME";
}else{
$object3[$key]['comparison_status'] = "NOT THE SAME";
$object3[$key][$o1i] = $object1[$key];
$object3[$key][$o2i] = $object2[$key];
}
}
}
return $object3;
}
?> francois-php at ceonizme dot fr ¶
10 years ago
to chinello at gmail dot com
I've had to use your function but it showed that the use of isset can't differentiate the NULL values from not setted values.
Here's a version that takes care of this subtility.
<?php
function array_diff_assoc_recursive($array1, $array2)
{
$difference = NULL;
foreach($array1 as $key => $value)
{
if(is_array($value))
{
if(!array_key_exists($key, $array2))
{
$difference[$key] = $value;
}
elseif(!is_array($array2[$key]))
{
$difference[$key] = $value;
}
else
{
$new_diff = array_diff_assoc_recursive($value, $array2[$key]);
if($new_diff != FALSE)
{
$difference[$key] = $new_diff;
}
}
}
elseif(!array_key_exists($key, $array2) || $array2[$key] != $value)
{
$difference[$key] = $value;
}
}
return !isset($difference) ? 0 : $difference;
}
?>
Hope that helps
François spark dot crz at gmail dot com ¶
7 years ago
Yet another recursive implementation, without if-else hell and with multiple parameters just like the original.
<?php
function recursiveDiff() {
$arrs = func_get_args();
$diff = call_user_func_array('array_diff_assoc', $arrs);
foreach(
$diff as $key => $value) {
if (!is_array($value))
continue;$children = array_map(function($arr) use($key){
return $arr[$key];
}, $arrs);$diff[$key] = call_user_func_array(__FUNCTION__, $children);
}
return
$diff;
}
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4