compare an array using call back function

 <?php

function key_compare_func($a, $b)

{

    if ($a === $b) {

        return 0;

    }

}

$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);

echo "<br><br>";

function key_compare_func1($a, $b)

{

    if ($a === $b) {

        return 1;

    }

}

$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");

$array2 = array("a" => "green", "yellow", "red");

$result = array_diff_uassoc($array1, $array2, "key_compare_func1");

print_r($result);

Depending on the return value   of the functions the output  will be inverted