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;
}
?>
array_diff_key
(PHP 5 >= 5.1.0)
array_diff_key — 使用键名比较计算数组的差集
说明
array array_diff_key
( array $array1
, array $array2
[, array $ ...
] )
array_diff_key() 返回一个数组,该数组包括了所有出现在 array1 中但是未出现在任何其它参数数组中的键名的值。注意关联关系保留不变。本函数和 array_diff() 相同只除了比较是根据键名而不是值来进行的。
Example#1 array_diff_key() 例子
<?php
$array1 = array('blue' => 1, 'red' => 2, 'green' => 3, 'purple' => 4);
$array2 = array('green' => 5, 'blue' => 6, 'yellow' => 7, 'cyan' => 8);
var_dump(array_diff_key($array1, $array2));
?>
上例将输出:
array(2) { ["red"]=> int(2) ["purple"]=> int(4) }
在 key => value 对中的两个键名仅在 (string) $key1 === (string) $key2 时被认为相等。换句话说,执行的是严格类型检查,因此字符串的表达必须完全一样。
Note: 注意本函数只检查了多维数组中的一维。当然,可以用 array_diff_key($array1[0], $array2[0]); 来检查更深的维度。
参见 array_diff(),array_udiff(),array_diff_assoc(),array_diff_uassoc(),array_udiff_assoc(),array_udiff_uassoc(),array_diff_ukey(),array_intersect(),array_intersect_assoc(),array_intersect_uassoc(),array_intersect_key() 和 array_intersect_ukey()。
array_diff_key
sjungwirth at matrix-consultants dot com
28-Feb-2008 09:08
28-Feb-2008 09:08
coder at gs dot com
16-Feb-2008 11:00
16-Feb-2008 11:00
The PHP4 version below works only unidirectionally. If you switch the arrays around i.e. (ar2, ar1) you get different results than (ar1, ar2).
AiFiLTr0 [at host] invyl [dot] ath.cx
29-Nov-2007 02:56
29-Nov-2007 02:56
The recursive function suggested by '2ge at 2ge dot us' will provide you with empty arrays if there's no diff.
This variant of the function cleans up empty arrays and fixes a bug in the first suggested version. It works 100%
.
<?php
function array_diff_key_recursive ($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;
}
?>
contact at autonoma dot fr
30-Jun-2007 02:01
30-Jun-2007 02:01
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 $result;
}
works for me, enjoy.
kwutzke @ somewhere in the net
20-Dec-2006 01:27
20-Dec-2006 01:27
PHP4 array_diff_key can be copied from the array_intersect_key implementation posted by some anonymous user on 2006-07-17. The only thing you have to do is to delete the '!' in the if and rename the function.
2ge at 2ge dot us
07-Mar-2006 08:28
07-Mar-2006 08:28
Hello, if you need diff key of n-dimensional arrays here is nice solution:
<?php
function n_array_diff ($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.
vlad_mustafin at ukr dot net
13-Jan-2006 04:39
13-Jan-2006 04:39
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 $result;
}
}
?>
ampf at egp dot up dot pt
25-Nov-2005 09:55
25-Nov-2005 09:55
Well, you could implement in the code something more powerfull:
http://www.php.net/manual/en/function.array-diff.php#31364
ml at iceni dot pl
07-Jun-2005 09:52
07-Jun-2005 09:52
You may obtain this function with PEAR Package PHP_Compat (http://pear.php.net/package/PHP_Compat)
Then using such code is quite useful
<?php
if(!function_exists('array_diff_key')){
require_once 'PHP/Compat/Function/array_diff_key.php';
}
?>
maxence at pontapreta dot net
27-May-2005 07:38
27-May-2005 07:38
Seems to be a great function, especially for n-dimensions arrays. The only problem is that I cannot find it in php 5.0.3 and 5.0.4. Does it really exist ?! :(
[20:27:05][maxence@conurb] ~/test2/php-5.0.4$ grep PHP_FUNCTION * -r | grep -i array_diff_key
[20:27:09][maxence@conurb] ~/test2/php-5.0.4$
nicolas at goinf dot com
14-Apr-2005 05:28
14-Apr-2005 05:28
Be aware that the last solution doesn't work if for any reason, two values are the same.
eric dot broersma at phil dot uu dot nl
05-Mar-2005 03:58
05-Mar-2005 03:58
<?php
function array_diff_key()
{
$args = func_get_args();
return array_flip(call_user_func_array('array_diff',
array_map('array_flip',$args)));
}
?>
denis noessler
23-Nov-2004 01:07
23-Nov-2004 01:07
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;
}
}
