array_intersect_uassoc

<?

function myfunction($key1, $key2) {
    if ($key1 == $key2)
        return 0;
    else if ($key1 > $key2)
        return 1;
    else
        return -1;
}

$array1 = array("a" => 0, "b" => 1, "c" => 2, "d" => 3);
$array2 = array("a" => 0, "b" => 4, "e" => 2, "f" => 5);
$key_compare_func = "myfunction";

$return = array_intersect_uassoc($array1, $array2, $key_compare_func);

print_r($return);

?>

Array
(
    [a] => 0
)

<?

function myfunction($key1, $key2) {
    if ($key1 == $key2)
        return 0;
    else if ($key1 > $key2)
        return 1;
    else
        return -1;
}

$array1 = array("a" => 0, "b" => 1, "c" => 2, "d" => 3);
$array2 = array("a" => 0, "b" => 4, "e" => 2, "f" => 5);
$array3 = array("a" => 0, "b" => 4, "e" => 2, "f" => 5);
$key_compare_func = "myfunction";

$return = array_intersect_uassoc($array1, $array2, $array3, $key_compare_func);

print_r($return);

?>

Array
(
    [a] => 0
)