Using PHP's array_uintersect() to Compute Array Intersection with a Callback Function

The array_uintersect() function returns an array containing all values that exist in the first array and also appear in all other arrays passed as arguments, where the comparison of values is performed by a user‑provided callback function. The callback must return an integer less than, equal to, or greater than zero when the first argument is considered less than, equal to, or greater than the second argument.

Parameters

array1 : The first array.

array2 : The second array (additional arrays can be supplied).

data_compare_func : A callable that compares two values and returns an integer (<0, 0, >0) indicating their ordering.

Return value

An array containing all values from array1 that are also present in every other array argument, according to the comparison performed by the callback.

Example

<?php
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "d" => "red");
$array2 = array("a" => "GREEN", "b" => "brown", "c" => "yellow", "d" => "red");
print_r(array_uintersect($array1, $array2, "strcasecmp"));
?>

Output

Array
(
    [a] => green
    [b] => brown
    [0] => red
)