There are `Constants` that point to values and then there are `Constant` values; any `String` or `Number` or `RegExp` literal is a `Constant`. `true` and `false` are constants of the `Boolean` Type. `undefined` is still a type, I agree - `typeof` makes that very clear. It's `null` that I'm not sure of. `null` isn't recognized as a type by any measurement that I can identify; it's one value, always, and JavaScript sees it as a plain `object`. I don't know what to make of that.

I would like to be convinced one way or the other about `null` so please keep trying =P