PHP 7.0.6 Released

    array_diff_assoc

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

    array_diff_assoc — Computes the difference of arrays with additional index check

    Description

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

    Compares array1 against array2 and returns the difference. Unlike array_diff() the array keys are also used in the comparison.

    Parameters

    array1

    The array to compare from

    array2

    An array to compare against

    ...

    More arrays to compare against

    Return Values

    Returns an array containing all the values from array1 that are not present in any of the other arrays.

    Examples

    Example #1 array_diff_assoc() example

    In this example you see the "a" => "green" pair is present in both arrays and thus it is not in the output from the function. Unlike this, the pair 0 => "red" is in the output because in the second argument "red" has key which is 1.

    <?php
    $array1     = array("a" => "green", "b" => "brown", "c" => "blue", "red");
    $array2 = array("a" => "green", "yellow", "red");
    $result = array_diff_assoc($array1, $array2);
    print_r($result);
    ?>

    The above example will output:

    Array
(
    [b] => brown
    [c] => blue
    [0] => red
)

    Example #2 array_diff_assoc() example

    Two values from key => value pairs are considered equal only if (string) $elem1 === (string) $elem2 . In other words a strict check takes place so the string representations must be the same.

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

    The above example will output:

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

    Notes

    Note: This function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using, for example, array_diff_assoc($array1[0], $array2[0]);.

    Note: Ensure you pass arguments in the correct order when comparing similar arrays with more keys. The new array should be the first in the list.

    See Also

    • array_diff() - Computes the difference of arrays
    • 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() - Computes the intersection of arrays
    • array_intersect_assoc() - Computes the intersection of arrays with additional index check

    User Contributed Notes

    Giosh
    3 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
      }
    }
    chinello at gmail dot com
    9 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).]
    Michael Richey
    2 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
    )
    Alexander Podgorny
    9 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
    ?>
    contact at pascalopitz dot com
    9 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
    )
    carl at thep dot lu dot se
    12 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.
    cedric at daneel dot net
    8 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;
        }
    ?>
    benjamin at moonfactory dot co dot jp
    11 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 ;
        }
    }

    ?>
    news_yodpeirs at thoftware dot de
    4 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).
    telefoontoestel at hotmail dot com
    2 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;
    }
    ?>
    francois-php at ceonizme dot fr
    1 year 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
    shadow_games at abv dot bg
    1 year 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;
        }
    ?>
    dev5er6 at gmail dot com
    2 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;
    }

    ?>
    jrajpu10 at gmail dot com
    7 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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