array_count_values
array_diff_key
Array Functions
PHP Manual

# 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

array_count_values
array_diff_key
Array Functions
PHP Manual