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
}
}
array_diff_assoc
(PHP 4 >= 4.3.0, PHP 5, PHP 7)
array_diff_assoc — 추가적인 인덱스 확인과 함께 배열 차이를 계산
설명
array array_diff_assoc
( array
$array1
, array $array2
[, array $...
] )
array1를 array2에 비교하고
차이를 반환합니다. array_diff()와 달리 배열 키를 비교에
사용합니다.
인수
-
array1 -
비교할 원본 배열
-
array2 -
비교할 대상 배열
-
... -
추가 대상 배열
반환값
다른 배열에 존재하지 않는 array1의 모든 값을 가지는
array를 반환합니다.
예제
Example #1 array_diff_assoc() 예제
이 예제에서 "a" => "green" 쌍이 두 배열에 모두 존재하므로 함수에서 출력하지 않습니다. 이와 달리, 0 =>> "red" 쌍은 출력하는데, 두번째 인수의 "red"는 키가 1이기 때문입니다.
<?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);
?>
위 예제의 출력:
Array
(
[b] => brown
[c] => blue
[0] => red
)
Example #2 array_diff_assoc() 예제
key => value 쌍에서 두 값은 (string) $elem1 === (string) $elem2 일 때만 동일하다고 간주합니다. 즉, 엄격한 확인을 하므로 문자열 표현이 동일해야 합니다.
<?php
$array1 = array(0, 1, 2);
$array2 = array("00", "01", "2");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
위 예제의 출력:
Array
(
[0] => 0
[1] => 1
)
주의
Note: 이 함수는 n차원 배열의 1차원만 확인합니다. 물론, 깊은 차원은 array_diff_assoc($array1[0], $array2[0]);처럼 확인할 수 있습니다.
참고
- array_diff() - 배열 차이를 계산
- array_intersect() - 배열의 교집합을 계산
- array_intersect_assoc() - 인덱스 검사과 함께 배열의 교집합을 계산
add a note
User Contributed Notes 18 notes
Giosh ¶
11 years ago
dev5er6 at gmail dot com ¶
10 years ago
Works more like the original function:
<?php
function 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 $diff;
}
?>
telefoontoestel at hotmail dot com ¶
10 years ago
an earlier post for recursive array_diff_assoc failed because isset returned false on an array element containing a null value. I updated the code so it compares null values too.
<?php
function array_diff_assoc_recursive($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 ¶
10 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,$a)));
// returns
array
(
[c] => 3
[d] => 4
)
chinello at gmail dot com ¶
17 years ago
The following will recursively do an array_diff_assoc, which will calculate differences on a multi-dimensional level. This not display any notices if a key don't exist and if error_reporting is set to E_ALL:
<?php
function array_diff_assoc_recursive($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).]
contact at pascalopitz dot com ¶
17 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, $a));
?>
echoes:
Array
(
)
Array
(
[g] => g
)
benjamin at moonfactory dot co dot jp ¶
19 years ago
Hi all,
For php versions < 4.3...
<?php
/**
* array_diff_assoc for version < 4.3
**/
if (!function_exists('array_diff_assoc'))
{
function array_diff_assoc($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 $r ;
}
}
?>
tero dot lahtinen at iki dot fi ¶
6 years ago
array_diff_assoc will fail, if a value is something that can not be converted to a string.
cedric at daneel dot net ¶
16 years ago
To diff between n-dimensional array, juste use this :
<?php
function array_diff_values($tab1, $tab2)
{
$result = array();
foreach($tab1 as $values) if(! in_array($values, $tab2)) $result[] = $values;
return $result;
}
?>
carl at thep dot lu dot se ¶
20 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");
$b = array(1, 3); // Elements to get rid of
foreach($b as $e)
unset($a[$e]);
?>
Of course this makes most sense if $b has many elements or is dynamically generated.
jrajpu10 at gmail dot com ¶
15 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);
// array_diff will not work here, array_diff_assoc works as it takes the key // in account.
$dups = array_diff_assoc($arr, $uniques);
print_r($dups);
?>
Note: The index of the $dups is not in strict sequential order as expected by C programmer.
Alexander Podgorny ¶
17 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,$array2);
// yields: array("b","c") the duplicate "a" values are removed
?>
news_yodpeirs at thoftware dot de ¶
12 years ago
A quite simple (yet not very efficient) way to compare the first level of arrays which have values that are not strings:
array_map('unserialize',array_diff_assoc(array_map('serialize',$arr1),array_map('serialize',$arr2)))
Might be useful for debugging (that's what I use it for).
spark dot crz at gmail dot com ¶
6 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 ¶
3 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 $diffs;
}
?>
shadow_games at abv dot bg ¶
9 years ago
there is a functiont that i searched long enough now i have created it so someone else to find it if he need it ;]
<?php
function compare_two_object_recursive($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;
}
?>
spark dot crz at gmail dot com ¶
6 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 $diff;
}
francois-php at ceonizme dot fr ¶
9 years ago
to chinello at gmail dot com
I've had to use your function but it showed that the use of isset can't differentiate the NULL values from not setted values.
Here's a version that takes care of this subtility.
<?php
function array_diff_assoc_recursive($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
