array_count_values
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
?>
array_diff_assoc
(PHP 4 >= 4.3.0, PHP 5)
array_diff_assoc — Berechnet den Unterschied zwischen Arrays mit zusätzlicher Indexprüfung
Beschreibung
array array_diff_assoc
( array
$array1
, array $array2
[, array $...
] )
Vergleicht array1 mit array2 und
gibt den Unterschied zurück. Im Gegensatz zu array_diff()
werden die Schlüssel des Arrays beim Vergleich herangezogen.
Parameter-Liste
-
array1 -
Das Array, das verglichen werden soll
-
array2 -
Das Array, mit dem verglichen werden soll
-
... -
Weitere Arrays, mit denen vergleichen werden soll
Rückgabewerte
Gibt ein Array zurück, das alle Werte aus
array1 enthält, die in keinem der
anderen Arrays vorhanden ist.
Beispiele
Beispiel #1 array_diff_assoc()-Beispiel
In diesem Beispiel sieht man, dass das "a" => "gruen"-Paar in beiden Arrays enthalten ist und daher nicht in der Ausgabe der Funktion auftaucht. Andererseits ist das Paar 0 => "rot" in der Ausgabe, weil "red" im zweiten Array den Wert 1 enthält.
<?php
$array1 = array("a" => "gruen", "b" => "braun", "c" => "blau", "rot");
$array2 = array("a" => "gruen", "gelb", "rot");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Array
(
[b] => braun
[c] => blau
[0] => rot
)
Beispiel #2 array_diff_assoc()-Beispiel
Zwei Werte von Schlüssel => Wert-Paaren werden nur dann als gleich betrachtet, wenn (string) $elem1 === (string) $elem2 gilt. Anders ausgedrückt findet eine strikte Prüfung statt, in der die String-Repräsentationen gleich sein müssen.
<?php
$array1 = array(0, 1, 2);
$array2 = array("00", "01", "2");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Array
(
[0] => 0
[1] => 1
)
Anmerkungen
Hinweis: Diese Funktion überprüft nur eine Dimension eines n-dimensionalen Arrays. Natürlich kann man tiefere Dimensionen überprüfen, indem man zum Beispiel array_diff_assoc($array1[0], $array2[0]); verwendet.
Siehe auch
- array_diff() - Ermittelt die Unterschiede zwischen Arrays
- array_intersect() - Ermittelt die Schnittmenge von Arrays
- array_intersect_assoc() - Ermittelt die Schnittmenge von Arrays mit Indexprüfung
add a note
User Contributed Notes
array_diff_assoc - [10 notes]
Alexander Podgorny ¶
6 years ago
Giosh ¶
2 months ago
The array_diff_assoc_array from "chinello at gmail dot com" (and others) will not work for arrays with null values. That's because !isset is true when an array key doesn't exists or is set to null.
(sorry for the changed indent-style)
<?php
function array_diff_assoc_recursive($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
}
}
Michael Richey ¶
17 days 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,$a)));
// returns
array
(
[c] => 3
[d] => 4
)
benjamin at moonfactory dot co dot jp ¶
8 years ago
Hi all,
For php versions < 4.3...
<?php
/**
* array_diff_assoc for version < 4.3
**/
if (!function_exists('array_diff_assoc'))
{
function array_diff_assoc($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 ;
}
}
?>
carl at thep dot lu dot se ¶
10 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 $b has many elements or is dynamically generated.
news_yodpeirs at thoftware dot de ¶
1 year ago
A quite simple (yet not very efficient) way to compare the first level of arrays which have values that are not strings:
array_map('unserialize',array_diff_assoc(array_map('serialize',$arr1),array_map('serialize',$arr2)))
Might be useful for debugging (that's what I use it for).
jrajpu10 at gmail dot com ¶
4 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.
contact at pascalopitz dot com ¶
6 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, $a));
?>
echoes:
Array
(
)
Array
(
[g] => g
)
chinello at gmail dot com ¶
6 years ago
The following will recursively do an array_diff_assoc, which will calculate differences on a multi-dimensional level. This not display any notices if a key don't exist and if error_reporting is set to E_ALL:
<?php
function array_diff_assoc_recursive($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 : $difference;
}
?>
[NOTE BY danbrown AT php DOT net: This is a combination of efforts from previous notes deleted. Contributors included (Michael Johnson), (jochem AT iamjochem DAWT com), (sc1n AT yahoo DOT com), and (anders DOT carlsson AT mds DOT mdh DOT se).]
cedric at daneel dot net ¶
6 years ago
To diff between n-dimensional array, juste use this :
<?php
function array_diff_values($tab1, $tab2)
{
$result = array();
foreach($tab1 as $values) if(! in_array($values, $tab2)) $result[] = $values;
return $result;
}
?>