Project D

Objective:

Inheritance

All of the following classes may be placed in the same file.

• Create a class called Amphibian.
• Add two methods, moveInWater() and moveOnLand() that announce themselves.
• From Amphibian, inherit a class called Frog. Do not define any methods in this class.
• Create a public class named FrogTest. In main(), create a Frog, upcast it to Amphibian and demonstrate that all the methods work.

Polymorphism

Now, test for polymorphic behavior:

• Modify your Frog class so that it overrides the method definitions from the base class (provides new definitions using the same method signatures).
• The methods should identify the object as a Frog.
• Name your classes Amphibian2, Frog2 and FrogTest2.
• Note what happens in main(). Did the behavior change?

Submit your work via the CATE form for Project D.

Legend: method/function keyword literal/identifier

2007/03/12