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Last updated: Tue, 19 Sep 2006


(PHP 4 >= 4.3.0, PHP 5)

array_diff_assoc -- Computes the difference of arrays with additional index check


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

array_diff_assoc() returns an array containing all the values from array1 that are not present in any of the other arguments. Note that the keys are used in the comparison unlike array_diff().

Example 1. array_diff_assoc() example

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

The above example will output:

    [b] => brown
    [c] => blue
    [0] => red

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

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.

Note: Please note that 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]);.

See also array_diff(), array_intersect(), and array_intersect_assoc().

Last updated: Tue, 19 Sep 2006