if (isset($_COOKIE['username'])) { setcookie('username', '', time() - 3600, '/'); unset($_COOKIE['username']); }
setcookie('username', '', time() - 3600, '/');This code directly sets the 'username' cookie's expiration time to a past date and time which will automatically delete the cookie from the browser. Package Library: PHP has built-in functions to handle cookies and does not require any external library.