(PHP 5, PHP 7, PHP 8)
array_diff_uassoc — Computes the difference of arrays with additional index check which is performed by a user supplied callback function
Compares array
against arrays
and returns the difference. Unlike array_diff() the array keys are used in the comparison.
Unlike array_diff_assoc() a user supplied callback function is used for the indices comparison, not internal function.
array
The array to compare from
arrays
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.
Returns an array containing all the entries from array
that are not present in any of the other arrays.
Example #1 array_diff_uassoc() example
In this 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 the key of "red"
is automatically assigned to 0
in the first array, whereas it is assigned to 1
in the second array as the key 0
is already taken by yellow
.
<?php
function key_compare_func($a, $b)
{
return $a <=> $b;
}
$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.
Note:
This function only checks one dimension of an n-dimensional array. It is possible to check deeper dimensions by using, for example,
array_diff_uassoc($array1[0], $array2[0], "key_compare_func");
.