array_count_values
To diff between n-dimensional array, juste use this :
function array_diff_values($tab1, $tab2)
{
$result = array();
foreach($tab1 as $values) if(! in_array($values, $tab2)) $result[] = $values;
return $result;
}
array_diff_assoc
(PHP 4 >= 4.3.0, PHP 5)
array_diff_assoc — 인덱스 검사와 함께 배열간의 차이를 계산한다
설명
array array_diff_assoc
( array $array1
, array $array2
[, array $ ...
] )
array_diff_assoc()는 array1 중에서 다른 인자에서 존재하지 않는 모든 값들을 포함하는 배열을 반환한다. 이 함수는 array_diff()과 달리 비교시에 키가 사용된다는것에 주의한다.
Example#1 array_diff_assoc() 예제코드
<?php
$array1 = array ("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array ("a" => "green", "yellow", "red");
$result = array_diff_assoc ($array1, $array2);
/* The result is:
Array
(
[b] => brown
[c] => blue
[0] => red
)
*/
?>
위 예제코드에서 "a" => "green" 쌍은 두 배열에 모두 존재하기 때문에 이 함수의 출력에서 존재하지 않는다. 이와 달리, 0 => "red" 쌍은 출력에 보이는데 그 이유는 두번째 인자에서 "red" 가 1 이라는 키를 갖기 때문이다.
key => value 쌍에서 두 구성요소가 동치라고 볼수 있는 때는 (string) $elem1 === (string) $elem2 일때 만이다. 달리 말하면 엄격한 타입 검사는 문자열 대표성이 동일해야 한다는것이다.
Note: 이 함수는 n-차원 배열의 한개 차원만 검사한다는것에 주의한다. 물론 array_diff_assoc($array1[0], $array2[0]);와 같은 방법으로 내부 차원을 검사할수 있다.
array_diff(), array_intersect(), array_intersect_assoc() 참고.
add a note
User Contributed Notesarray_diff_assoc
cedric at daneel dot net
21-May-2007 06:01
21-May-2007 06:01
contact at pascalopitz dot com
11-Apr-2007 04:14
11-Apr-2007 04:14
The direction of the arguments does actually make a difference:
<?
$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, $a));
?>
echoes:
Array
(
)
Array
(
[g] => g
)
chinello at gmail dot com
18-Mar-2007 11:33
18-Mar-2007 11:33
A small modification for array_diff_assoc_recursive from 'sc1n at yahoo dot com' , to not display any notices if a key don't exist and if error_reporting is set to E_ALL:
<?php
function array_diff_assoc_recursive($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;
}
?>
Alexander Podgorny
30-May-2006 02:30
30-May-2006 02:30
NOTE: the diff_array also removes all the duplicate values that match to the values in the second array:
<?
$array1 = array("a","b","c","a","a");
$array2 = array("a");
$diff = array_diff($array1,$array2);
// yields: array("b","c") the duplicate "a" values are removed
?>
benjamin at moonfactory dot co dot jp
11-Jan-2005 09:56
11-Jan-2005 09:56
Hi all,
For php versions < 4.3...
<?php
/**
* array_diff_assoc for version < 4.3
**/
if (!function_exists('array_diff_assoc'))
{
function array_diff_assoc($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 ;
}
}
Hope there's no bug,
cheers
?>
aidan at php dot net
09-Jun-2004 06:34
09-Jun-2004 06:34
This functionality is now implemented in the PEAR package PHP_Compat.
More information about using this function without upgrading your version of PHP can be found on the below link:
http://pear.php.net/package/PHP_Compat
Michael Johnson
26-Oct-2003 12:20
26-Oct-2003 12:20
[jochem at iamjochem dawt com]
Here is a slightly enhanced version of Micheal Johnsons function.
This version accepts arguments in the same way as
array_diff_assoc (i.e. you can pass as many arrays as you want - any
arguments that are not arrays are ignored). If the first argument is not an array you automatically get empty array back:
The point of the function is to return all values in the first array
whose keys (only keys are checked!) are not present in any subsequently passed arrays.
[original post]
array_diff_assoc() requires that both the key and the value pairs match. To match based on keys only, try this function.
<?php
function array_diff_keys()
{
$args = func_get_args();
$res = $args[0];
if(!is_array($res)) {
return array();
}
for($i=1;$i<count($args);$i++) {
if(!is_array($args[$i])) {
continue;
}
foreach ($args[$i] as $key => $data) {
unset($res[$key]);
}
}
return $res;
}
// Example
$a = array('a' => '1', 'b' => '2', 'c' => '3');
$b = array('a' => '2', 'b' => '2', 'e' => '4');
// Yields array('a' => '1', 'c' => '3')
// Note that the 'a' index is not removed (as one might expect)
$c = array_diff_assoc($a, $b);
// Yields array('c' => '3')
$d = array_diff_keys($a, $b);
?>
sc1n at yahoo dot com
11-Jul-2003 12:10
11-Jul-2003 12:10
[anders dot carlsson at mds dot mdh dot se]
The user contributed array_diff_assoc_recursive function is good except for the original array_diff_assoc always (?) returns an array.
Therefore I propose that $difference is initially set to an empty array (and the array is always returned), and the comparison against FALSE is replaced by count($new_diff). At least that's the modifications I made to run it they way my code expects.
[original post]
The following will recursively do an array_diff_assoc, which will calculate differences on a multi-dimensional level. (Forgive me if the braces do not line up, the note script did not like my tabs, and gave me trouble on some spaces.)
<?php
function array_diff_assoc_recursive($array1, $array2)
{
foreach($array1 as $key => $value)
{
if(is_array($value))
{
if(!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;
}
?>
carl at thep dot lu dot se
09-May-2003 02:55
09-May-2003 02:55
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.