1. Advanced Java Programming
Session #, Speaker Name
Advanced Java Programming
CSS446
Spring 2014
Nan Wang
08/24/11

2. Chapter Goals To learn about inheritance
To implement subclasses that inherit and override superclass methods

3. Inheritance Hierarchies
Inheritance is a relationship between a more general class (called the super­class) and a more specialized class (called the subclass).

4. Inheritance Hierarchies
The subclass inherits data and behavior from the superclass.
You can always use a subclass object in place of a superclass object.
E.g.
void processVehicle(Vehicle v)
Because Car is a subclass of Vehicle, you can call that method with a Car object:
Car myCar = new Car(. . .);
processVehicle(myCar);

5. Example

6. Implementing Subclasses
Subclass inherits all methods that it does not override.

7. choiceQuestion.setAnswer("2");
question.addChoice("Canada", true);
setAnswer(choiceString);

8. Implementing Subclasses
Override:
Subclass can override a superclass method by providing a new implementation.
An overriding method can extend or replace the  functionality of the superclass method.
Display the question text.
Display the answer choices.

9. Override display() in subclass
Display the question text.
Display the answer choices.
Use the reserved word super to call a superclass method

10. Constructor with Superclass Initializer

12. Override vs. Overload

13. Program Assignment 2

14. Program Assignment 2 Due Date: 1/30/2014 Submit to usm.java@gmail.com
P1: 100 points
Bonus: P2: 20 points and P3 30 points