CS 201 - Lab 1

For this lab you will implement a class that represents a pocketful of change.  The goal is for you to get acquainted (or re-acquainted) with Java and to practice using the Eclipse Java development environment.

Getting Started

Download lab1.zip.  (Save it somewhere you can easily find it again: for example, on the Desktop.)

Start Eclipse.  Choose File->Import...->General->Existing Projects Into Workspace.  Choose Select archive file.  Choose lab1.zip from wherever you saved it earlier.  Choose Finish.

You should now see the lab1 project in the Package Explorer window.

Implementing the Coins class

Implement the class called Coins, which is in the file called Coins.java.  This file can be found by expanding the lab1 project, then the src folder, and then the edu.ycp.cs201.lab1 package.  Double click on the file to open it in an editor window.

The class should have fields (member variables) for each coin type listed below:

pennies, nickels, dimes, and quarters

The class should provide the following methods:

  1. A zero-parameter constructor that initializes the new object so that there are 0 pennies, 0 nickels, 0 dimes, and 0 quarters.

  2. A 4-parameter constructor that takes the numbers of pennies, nickels, dimes, and quarters (in that order), and initializes the respective fields.

  3. findCentsValue calculates and returns the total value of the coins in cents, as an integer.

  4. findDollars calculates and returns the value in dollars, as an integer. Any fractional part of a dollar should be discarded: for example, if the coins total $1.37, then this method should return the value 1.

  5. findChange calculates and returns the value of the leftover change (after the dollars are removed) as an integer. For example, if the coins total $1.37, then this method should return the value 37.


Right-click on CoinsTest.java in the package explorer, and choose Run As...->JUnit Test.  This will run the JUnit tests for the Coins class.  If you have correctly implemented the Coins class, you will see a green bar, indicating that all tests have succeeded.