(PHP 5 >= 5.1.0, PHP 7, PHP 8)
array_diff_key — Berechnet den Unterschied zwischen Arrays, indem es die Schlüssel vergleicht
Vergleicht die Schlüssel von array mit
den Schlüsseln von arrays und gibt die
Unterschiede zurück. Diese Funktion arbeitet wie
array_diff() mit dem Unterschied, dass der Vergleich
mit den Schlüsseln statt den Werten arbeitet.
arrayDas Array, das verglichen werden soll
arraysArrays zum Vergleichen
Gibt ein Array mit allen Einträgen von
array zurück, deren Schlüssel in keinem
der anderen Arrays vorhanden sind.
| Version | Beschreibung |
|---|---|
| 8.0.0 | Diese Funktion kann jetzt mit nur einem Parameter aufgerufen werden. Zuvor waren mindestens zwei Parameter erforderlich. |
Beispiel #1 array_diff_key()-Beispiel
Die beiden Schlüssel des Schlüssel => Wert-Paares
werden als gleich erachtet, genau dann wenn
(string) $Schlüssel1 === (string) $Schlüssel2 .
Anders ausgedrückt findet eine strikte Prüfung statt, in der die
String-Repräsentationen gleich sein müssen.
<?php
$array1 = array('blau' => 1, 'rot' => 2, 'grün' => 3, 'violett' => 4);
$array2 = array('grün' => 5, 'gelb' => 7, 'türkis' => 8);
var_dump(array_diff_key($array1, $array2));
?>Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
array(3) {
["blau"]=>
int(1)
["rot"]=>
int(2)
["violett"]=>
int(4)
}
<?php
$array1 = array('blau' => 1, 'rot' => 2, 'grün' => 3, 'violett' => 4);
$array2 = array('grün' => 5, 'gelb' => 7, 'türkis' => 8);
$array3 = array('blau' => 6, 'gelb' => 7, 'blasslila' => 8);
var_dump(array_diff_key($array1, $array2, $array3));
?>Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
array(2) {
["rot"]=>
int(2)
["violett"]=>
int(4)
}
Hinweis:
Diese Funktion überprüft nur eine Dimension eines n-dimensionalen Arrays. Natürlich kann man tiefere Dimensionen überprüfen, indem man
array_diff_key($array1[0], $array2[0]);verwendet.
To return the unique elements (those with a key that exists only once in either array but not in both) try:
function array_unique_diff ($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, )Improved recursive version.
<?php
/**
* @author Gajus Kuizinas <gk@anuary.com>
* @version 1.0.0 (2013 03 19)
*/
function array_diff_key_recursive (array $arr1, array $arr2) {
$diff = array_diff_key($arr1, $arr2);
$intersect = array_intersect_key($arr1, $arr2);
foreach ($intersect as $k => $v) {
if (is_array($arr1[$k]) && is_array($arr2[$k])) {
$d = array_diff_key_recursive($arr1[$k], $arr2[$k]);
if ($d) {
$diff[$k] = $d;
}
}
}
return $diff;
}
?>
An up to date version is maintained at https://github.com/gajus/flow/blob/master/flow.inc.php#L337. 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 $r;
}
?>Seems to be a great function, especially for n-dimensions arrays. The only problem is that I cannot find it in php 5.0.3 and 5.0.4. Does it really exist ?! :(
[20:27:05][maxence@conurb] ~/test2/php-5.0.4$ grep PHP_FUNCTION * -r | grep -i array_diff_key
[20:27:09][maxence@conurb] ~/test2/php-5.0.4$The recursive function suggested by '2ge at 2ge dot us' will provide you with empty arrays if there's no diff.
This variant of the function cleans up empty arrays and fixes a bug in the first suggested version. It works 100%
.
<?php
function array_diff_key_recursive ($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 $r;
}
?>The PHP4 version below works only unidirectionally. If you switch the arrays around i.e. (ar2, ar1) you get different results than (ar1, ar2).Here's a simple function that returns true if all keys in the first array are found in the second array, and false if they aren't.
function same_keys ($a1, $a2) {
$same = false;
if (!array_diff_key($a1, $a2)) {
$same = true;
foreach ($a1 as $k => $v) {
if (is_array($v) && !same_keys($v, $a2[$k])) {
$same = false;
break;
}
}
}
return $same;
}
To check if two arrays have the same structure, ignoring values, execute the function twice, the second time with the arguments reversed.Well, you could implement in the code something more powerfull:
http://www.php.net/manual/en/function.array-diff.php#31364 you can use this function for return the difference of two array !
<?php
function array_unique_diff_key ($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();
}
?>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;
}
}
?>