PHP 5.4.33 Released

array_diff_assoc

(PHP 4 >= 4.3.0, PHP 5)

array_diff_assocCalcola la differenza tra due o più array con un ulteriore controllo sull'indice

Descrizione

array array_diff_assoc ( array $array1 , array $array2 [, array $ ... ] )

array_diff_assoc() restituisce un array contenente tutti i valori di array1 che non sono presenti in alcuno degli altri array. Si noti che le chiavi sono utilizzate nel confronto, diversamente da array_diff().

Example #1 esempio di array_diff_assoc()

<?php
$array1 
= array("a" => "verde""b" => "marrone""c" => "blu""rosso");
$array2 = array("a" => "verde""giallo""rosso");
$result array_diff_assoc($array1$array2);
print_r($result);
?>

Il risultato è:

Array
(
    [b] => marrone
    [c] => blu
    [0] => rosso
)

Nell'esempio si vede che la coppia "a" => "verde" è presente in entrambi gli array e quindi non è nel risultato della funzione. Invece, la coppia 0 => "rosso" è nel risultato perché nel secondo argomento "red" cha come chiave 1.

Due valori delle coppie chiave => valore sono considerati uguali solo se (string) $elem1 === (string) $elem2 . In altre parole c'è un controllo stringente che si accerta che le rappresentazioni sotto forma di stringa siano uguali.

Nota: Si noti che questa funzione controlla solo una dimensione di un array n-dimensionale. Ovviamente è possibile controllare le altre dimensioni usando array_diff_assoc($array1[0], $array2[0]);.

Vedere anche array_diff(), array_intersect(), and array_intersect_assoc().

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User Contributed Notes 14 notes

up
12
Michael Richey
1 year 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
)
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8
Giosh
1 year 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
  }
}
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6
chinello at gmail dot com
7 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).]
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6
Alexander Podgorny
8 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
?>
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3
benjamin at moonfactory dot co dot jp
9 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 ;
    }
}

?>
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3
carl at thep dot lu dot se
11 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 $b has many elements or is dynamically generated.
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1
news_yodpeirs at thoftware dot de
3 years ago
A quite simple (yet not very efficient) way to compare the first level of arrays which have values that are not strings:
array_map('unserialize',array_diff_assoc(array_map('serialize',$arr1),array_map('serialize',$arr2)))
Might be useful for debugging (that's what I use it for).
up
1
contact at pascalopitz dot com
7 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
)
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1
cedric at daneel dot net
7 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;
    }
?>
up
0
francois-php at ceonizme dot fr
23 days 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
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0
shadow_games at abv dot bg
3 months 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;
    }
?>
up
0
dev5er6 at gmail dot com
5 months 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;
}

?>
up
0
telefoontoestel at hotmail dot com
7 months 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;
}
?>
up
0
jrajpu10 at gmail dot com
5 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.
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