Objectives

• Construct and use Objects
• Design the public interface of a class
• Determine the instance variables necessary for a class
• Implement the shell of a class using stubs with comments
• Implement constructors
• Implement simple methods
• Access instance fields and local variables

Hand-in Requirements

All projects and laboratories will be submitted electronically through WebCT.  Zip up your entire project folder to submit as the source.  (Right click on the project folder and follow the SentTo link.) The project folder should include the following:

• Public Interface as a word or plaintext document
• Square.java
• SquareTest.java

Details

Implement a class Square that has methods double getSide(), String toString(), double calculateArea(), and double calculatePerimeter().  In the constructor, supply the side of the square.  To test the Square class instantiate two squares with different length sides and print the side, area and perimeter.  Be sure you test ALL of your methods.

1. Design the public interface for the Square Class.

   • How will you need to initialize a new square?  This will be your constructor.
   • What behavior will the Square class have?  This will be your methods.
   • What type of information will the Square class need to store to do its job.  This will be your private instance variables.

2. Setup:

   • Project/Folder name:  Square
   • New class with main method:  SquareTest

     public class SquareTest {
         public static void main(String[] args) {
     
         }
     }
     

   • New class:  Square

     public class Square {
     
     }
     

   • Save your classes in the square folder.
   • Compile your classes and run the SquareTest class.
   • Save your project.

3. Implement the class

   • Type in your square.java: your instance variables and stubs for the constructor and methods.  Compile your project to test for any bugs.
   • Fill in your constructor and methods.  Run your project often to check for bugs.
   • Test all of the methods in your class.  Make sure the behavior is correct by looking at your output!