A few questions about Java and design
T/F and an explanation if not T please
1. All user-defined interfaces are subtypes of the type Interface.
2. A method call is sent to an object and the method of the actual type is executed.
3. A data model specifies the user interface.
4. If classes B and C are subclasses of A, then any state variable of A is also a state variable of B and C.
I looked in the JavaDocs at Sun, but couldn't find a type Interface anywhere, but I think I remember hearing something about it. I think you have to use dispatching for #2, and #3 I really have no clue. For #4, does the visibility matter, or is it a state variable in B and C even if it was declared private in A?