subclass of component

[Roopa Bagur]

47. In the list below, which subclass(es) of Component cannot be directly instantiated:
a) Panel
b) Dialog
c) Container
d) Frame
What is the answer ?

[Valentin Crettaz]

I think all of them may be directly instantiated since none of them is abstract...
Correct me if I'm wrong..
Val

[Ragu Sivaraman]

I have to say its Dialog
Coz they dont have a dummy constructor
They need Frame to exist before they can be constructed
Any thought?
Ragu

[Valentin Crettaz]

Yeah I agree but I also think that the question could be formulated in a better way.
Val