[fendy3002]

It is surprising behavior, because if the code can be accessed inside the scope, it is safe to assume that any modification to it will change the state, since it is still inside closure. If they throw `s++` with accessing undefined variable error, it will be much better. It'll be better if they can catch it during compile / validating / linting level.

And yes, PHP's behavior is surprising too. Unless we're doing scratch PHP without any classes or frameworks, any temporary variables become non-intuitive.