CS 221 Lab--Inheritance
Fall 2006
Lecture Schedule TA (Sam Gardner) page

Lab 3: Using Abstract Classes & Methods

Due dates: This is a one week lab, so it will be due October 9.
The knowledge needed to write this program will be tested on the exam on Friday, so you should get as much of this done before the exam as you can. I think most of you should be able to finish it in the lab. If you do, demo it today, if not demo it next Monday, October 9

Problem: You will write a superclass Shape, and three subclasses that inherit from Shape. You will also need a driver to test your class hierarchy.
- Class Shape should include:
  - abstract methods: computerArea, computePerimeter;
  - constructor(s),
  - it should also include a method toString (you decide whether it should be abstract or not), and
  - any other methods and instance variables you think appropriate.
- Three subclasses: Rectangle, Circle, and Triangle that inherit from class Shape.
  - Include any instance variables and methods you think appropriate.
- Write a driver to test your Shape class hierarchy.
  - It should declare an array of at least five Shapes,
  - fill the array with objects of type Circle, Triangle, and Rectangle(hard coded if you want) then
  - print out the contents of each objects in the array, giving the original dimension of the object, the area, and the perimeter. For example the output might be:
```
Shape 1 is a circle with a radius of 4.5; its area is ____, its perimeter is _____.
Shape 2 is a rectangle with sides 4.4 and 3.2; its area is ___, its perimeter is ____.
Etc.
```
Be sure to use inheritance to do this problem. Do NOT hav a lot of if statemtments testing whether the shape is a triangle, circle or rectangle.