Problem Set 7

CMP 326: Programming Methods II
Lehman College, City University of New York
Fall 2012

This problem set covers Chapter 6.

Characterstic (5 points)

(Exercises #5, Page 464) Consider a class Characteristic that will be used in an online dating service to assess how compatible two people are. Its attributes are:

• description - A String that identifies the characteristic
• rating - An integer between 1 and 10 (inclusive) that indicates a person's desire for this characteristic in another person

Implement this class with the following methods:

• Write a constructor that sets the description of the characteristic to given String and sets the rating to zero to indicate that it has not yet been determined.
• Write a private method isValid(aRating) that returns true if the given rating is valid, that is, it is between 1 and 10
• Write a method setRating(aRating) that sets the rating to aRating if it is valid
• Write a method setRating() that reads a rating from the keyboard, insisting that the rating supplied by the user is valid

Name this program Characteristic

Motor Boat (5 points)

(Exercises #7, Page 359) Consider the class MotorBoat that represents motorboarts. A motorboat has attributes for:

• The capacity of the fuel tank (double)
• The amount of fuel in the tank (double)
• The maximum speed of the boat (double)
• The current speed of the boat (double)
• The efficiency of the boat's motor (double)
• The distance traveled (double)

The class has the following methods:

• MotorBoat() - Default constructor
• MotorBoat(double fuelCapacity, double fuelInTank, double maxSpeed, double efficiency, double distanceTraveled) - Constructor
• MotorBoat(double fuelCapacity, double maxSpeed, double efficiency) - Constructor
• setCurrentSpeed(double speed) - Change the current speed of the boat
• driveBoat(double time) - Operate the boat for an amount of time at the current speed
• refuelBoat(double fuel) - Refuel the boat with some amount of fuel
• getFuel() - Get the amount of fuel in the tank
• getDistanceTraveled() - Get the distance traveled so far
• equals(MotorBoat otherBoat) - Compare two MotorBoats for equality
• Implement get, and set methods for all attributes.

If the boat has efficiency e, the amount of fuel used when traveling at a speed s for time t is (e * (s^2) * t). The distance traveled in that time is (s * t).

Implement the class in Java and write some Java code to test all the functionality of the class.

Name these programs MotorBoat & MotorBoatDemo

Item Sales (5 points)

(Exercises #6, Page 358) Consider a class that keeps track of the sales of an item. An object of this class will have the attributes:

• Number Sold
• Total Sales (In Dollars)
• Total Discounts
• Cost per item
• Bulk Quantity
• Bulk discount percentage

And the following methods:

• ItemSales() - Default constructor
• ItemSales(double itemCost, int bulkQuantity, double discountPecentage) - Default constructor
• ItemSales(double itemCost) - Default constructor
• ItemSales(int bulkQuantity, double discountPercentage) - Default constructor
• registerSale(n) Records the sale of n items. If n is equal to or larger than the bulk quatity, the cost per item will be reduced by the bulk discount.
• displaySales() Displays the number sold, the total sales, and total discount.
• equals(ItemSales otherItem) - Compare two MotorBoats for equality
• Implement get, and set methods for all attributes.

Implement the class in Java and write some Java code to test the class.

Name these programs ItemSales & ItemSalesDemo