PHP - Cookie and Session Doesn't get Deleted Permanently - php

Question

I trigger the function below in all my web pages.
function refresh_user_auth() {
if (isset($_COOKIE["UserID"])) {
$_SESSION["UserIDS"] = $_COOKIE["UserID"];
setcookie("UserID", $_COOKIE["UserID"], time() + (86400 * 30), "/");
}
elseif (isset($_SESSION["UserIDS"])) {
$_SESSION["UserIDS"] = $_SESSION["UserIDS"];
setcookie("UserID", $_SESSION["UserIDS"], time() + (86400 * 30), "/");
}
}
I use the function below to log out but it doesn't seem to have logged me out when I visit other web pages on the website.
function unset_user_auth() {
if (isset($_COOKIE["UserID"])) {
unset($_COOKIE['UserID']);
$_COOKIE = array();
setcookie('UserID', '', time() - 36000);
}
if (isset($_SESSION["UserIDS"])) {
unset($_SESSION['UserIDS']);
$_SESSION = array();
session_destroy();
setcookie('UserIDS', '', time() - 36000);
}
}
Please, what am I doing wrong?

Answer 1

I'm not sure why you have to do that separately for cookie and session, you can do that all at once. When logging out, it isn't required to check if cookies are set and/or session is set if you're going to destroy both anyway (unless you have an option to save cookie for 'Remember me' function).
Here's an example from a comment in the PHP documentation for session_unset() function page. You could always refer to PHP documentation when in doubt. You'll find ample examples and use cases in the comments.
<?php
session_start();
session_unset();
session_destroy();
session_write_close();
setcookie(session_name(),'',0,'/');
session_regenerate_id(true);
?>