PHP Удалить cookie
if (isset($_COOKIE['key'])) {
unset($_COOKIE['key']);
setcookie('key', '', time() - 3600, '/'); // empty value and old timestamp
}
Wrong Answer
if (isset($_COOKIE['key'])) {
unset($_COOKIE['key']);
setcookie('key', '', time() - 3600, '/'); // empty value and old timestamp
}unset($_COOKIE['hello']);