array_diff_assoc

(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

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

Descrizione

array_diff_assoc(array $array, array ...$arrays): array

Confronta array con arrays e restituisce la differenza. A differenza di array_diff(), nel confronto vengono utilizzate anche le chiavi dell'array.

Elenco dei parametri

array

L'array da confrontare

arrays

Gli array con cui confrontare

Valori restituiti

Restituisce un array contenente tutti i valori dell' array che non sono presenti in nessuno degli altri array.

Esempi

Example #1 Esempio di array_diff_assoc()

In questo 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" ha come chiave 1.

<?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 precedente esempio visualizzerà:

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

Example #2 Esempio di array_diff_assoc()

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.

<?php
$array1
= array(0, 1, 2);
$array2 = array("00", "01", "2");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>

Il precedente esempio visualizzerà:

Array
(
    [0] => 0
    [1] => 1
    )

Note

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

Nota: Assicurarsi di passare gli argomenti nell'ordine corretto quando si confrontano array simili con più chiavi. Il nuovo array dovrebbe essere il primo nella lista.

Vedere anche:

  • array_diff() - Calcola la differenza di due o più array
  • array_diff_uassoc() - Computes the difference of arrays with additional index check which is performed by a user supplied callback function
  • array_udiff_assoc() - Computes the difference of arrays with additional index check, compares data by a callback function
  • array_udiff_uassoc() - Computes the difference of arrays with additional index check, compares data and indexes by a callback function
  • array_intersect() - Calcola l'intersezione degli arrays
  • array_intersect_assoc() - Calcola l'intersezione degli array con un ulteriore controllo sugli indici

add a note add a note

User Contributed Notes 18 notes

up
51
Giosh
11 years 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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4
dev5er6 at gmail dot com
9 years 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
5
telefoontoestel at hotmail dot com
10 years 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
16
Michael Richey
10 years 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
)
up
11
chinello at gmail dot com
17 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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9
contact at pascalopitz dot com
16 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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5
benjamin at moonfactory dot co dot jp
19 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 ;
    }
}

?>
up
2
tero dot lahtinen at iki dot fi
6 years ago
array_diff_assoc will fail, if a value is something that can not be converted to a string.
up
3
cedric at daneel dot net
16 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;
    }
?>
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3
carl at thep dot lu dot se
20 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.
up
1
jrajpu10 at gmail dot com
15 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.
up
3
Alexander Podgorny
17 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
?>
up
1
news_yodpeirs at thoftware dot de
12 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).
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2
spark dot crz at gmail dot com
5 years ago
Recursive implementation accepting multiple n-level-arrays as parameters:

<?php
function recursiveDiff() {
   
$arrs = func_get_args();
   
$first = array_shift($arrs);
   
$diff = [];

    foreach(
$first as $key => $value) {
       
$values = array_map(function($arr) use($key){
            if (
is_array($arr) && !array_key_exists($key, $arr))
                return
null;

            return
$arr[$key];
        },
$arrs);

        if (
in_array($value, $values))
            continue;

        if (
is_array($value)) {
           
array_unshift($values, $value);
           
$diff[$key] = call_user_func_array(__FUNCTION__, $values);
            continue;
        }

       
$diff[$key] = $first[$key];
    }

    return
$diff;
}
?>

The other attempt was cleaner but didn't work for all cases.
up
0
angujomondi at gmail dot com
2 years ago
For recursive diff of multiple arrays, exending solution provided by Gosh.

<?php

function array_diff_assoc_recursive(array $array, array ...$arrays)
    {
       
$func  = function($array1, $array2) use (&$func){
           
$difference = [];
            foreach (
$array1 as $key => $value) {
                if (
is_array($value)) {
                    if (!isset(
$array2[$key]) || !is_array($array2[$key])) {
                       
$difference[$key] = $value;
                    } else {
                       
$new_diff = $func($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;
        };
       
$diffs = $array;
        foreach (
$arrays as $_array) {
           
$diffs = $func($diffs, $_array);
        }
        return
$diffs;
    }

?>
up
1
shadow_games at abv dot bg
9 years 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;
    }
?>
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-2
spark dot crz at gmail dot com
5 years ago
Yet another recursive implementation, without if-else hell and with multiple parameters just like the original.

<?php
function recursiveDiff() {
   
$arrs = func_get_args();
   
$diff = call_user_func_array('array_diff_assoc', $arrs);

    foreach(
$diff as $key => $value) {
        if (!
is_array($value))
            continue;

       
$children = array_map(function($arr) use($key){
            return
$arr[$key];
        },
$arrs);

       
$diff[$key] = call_user_func_array(__FUNCTION__, $children);
    }

    return
$diff;
}
up
-4
francois-php at ceonizme dot fr
9 years 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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