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sfolax6776
Apr 12

Test Prep 11 - Dynamic Binding, Interfaces and Abstract Classes

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Edited: Apr 12

A. Dynamic Binding:

  1. When a super class type of object is declared, the reference(for instance, x) can point to either a _________ class object or a _________class object.

  2. If a method (say, do()) in super class is overridden in the subclass, in the above case, will x.do() call the super class version or sub class version?

  3. Down casting: if a super class reference points to a subclass object, and a "subclass only" method is called, a downcasting is needed to make the call otherwise compile time error will occur.

B. Interfaces:

  1. The story of last digit.

  2. How many interfaces can a class implement? why?

  3. Can interface type be used to declare objects?

C. Abstract Classes:

  1. What if a class implements only part of the interface?

  2. Can abstract classes become super classes?

  3. What if the abstract methods are not implemented in sub classes either?

D. Comparable Interface:

 

public interface Comparable{
int compareTo(Object obj);
}

E. Challenge of the Week: All MC questions of Chapter 4.

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