PHP Unset Session Variable

Unset is a function. Therefore you have to submit which variable has to be destroyed.

unset($var);

In your case

unset ($_SESSION["products"]);

If you need to reset whole session variable just call

session_destroy ();

You can unset session variable using:

1. session_unset - Frees all session variables (It is equal to using: $_SESSION = array(); for older deprecated code)
2. unset($_SESSION['Products']); - Unset only Products index in session variable. (Remember: You have to use like a function, not as you used)
3. session_destroy — Destroys all data registered to a session

To know the difference between using session_unset and session_destroy, read this SO answer. That helps.