array_diff_key
array_diff_ukey
Array Functions
PHP Manual

# array_diff_uassoc

Computes the difference of arrays with additional index check which is performed by a user supplied callback function

### Description

array array_diff_uassoc ( array `$array1` , array `$array2` [, array `$...` ], callable `$key_compare_func` )

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

Unlike array_diff_assoc an user supplied callback function is used for the indices comparison, not internal function.

### Parameters

`array1`

  The array to compare from

`array2`

  An array to compare against

`...`

  More arrays to compare against

`key_compare_func`

  The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.

  int callback ( mixed `$a`, mixed `$b` )

### Return Values

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

### Examples

Example #1 array_diff_uassoc example

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
function key_compare_func($a, $b)
{
if ($a === $b) {
return 0;
}
return ($a > $b)? 1:-1;
}
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "green", "yellow", "red");
$result = array_diff_uassoc($array1, $array2, "key_compare_func");
print_r($result);
?>`

The above example will output:

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

The equality of 2 indices is checked by the user supplied callback function.

### 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_uassoc($array1[0], $array2[0], "key_compare_func");.

### See Also

- array_diff
- array_diff_assoc
- array_udiff
- array_udiff_assoc
- array_udiff_uassoc
- array_intersect
- array_intersect_assoc
- array_uintersect
- array_uintersect_assoc
- array_uintersect_uassoc