> Yet you can absolutely write: > String str = "hello,"; > str += "world!"; So it's "immutable" for some lawyerish definition which does me no good.

`str` is a mutable reference to an immutable object. You can make the reference point to something else, but the object being pointed to is immutable, so eg if you pass it to a function, that function cannot change it under you. If you want to make the reference immutable, declare it as final. I don't think understanding the difference between a pointer and the value it points to is lawyerish.