Class Extension Java

Question

I have class A, and class B ( extends A ). I'm attempting to call out methods from class B, when B is cast as A. Is this possible?

Ex.

A myObject = new B();
myObject.myMethodFoundInB(param);

Answer 1

You can do it by casting back to B, ie:

A myObject = new B();
((B)myObject).myMethodFoundInB(param);

or, more safely:

A myObject = new B();
if (myObject instanceof B) {
    ((B)myObject).myMethodFoundInB(param);
}

Answer 2

If the method is not defined in parent then you wouldn't be able to call it using the parent class reference.

You may just define an abstract method myMethodFoundInB in your parent class and override in your child class. Then you will be able to call myMethodFoundInB using parent class reference as well.

Answer 3

This is only possible if "myMethodFoundInB" is declared in class A, which I'm guessing it isnt.