Outer is (implicitly) typed as an int, so it cannot be null under any circumstances. The default value for ints is 0. However, outer will be 2 in this case. Environment capture makes it do what it looks like, just like javascript.

I don't know what you mean by "has closures but not when evented."

If outer were anything but 2 in the click handler, it wouldn't be a closure, which by definition closes over its environment.

outer will be 2

A closure is created for the anonymous function, allowing access (by reference) to the non-local variables in the containing method.

Ok I tested it and you have access to outer here. I must be thinking of something else. Asynchronous web requests?