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