Lab Exam 20/9/2005

We want to realize a program for collecting statistical data about car sales. For each car, the following information is stored:

brand (a string),
horse power (an integer),
price (a double),
name of the owner of the car (a string); if the car has not been sold, the name of the owner is null.

Part 1. Write a class Car that implements the following methods:

Car(String b, int hp) : constructor that creates an object representing an car whose brand is b, whose horse power is hp, and which has not been sold yet;
String getBrand() : that returns the brand of the car;
int getHP() : that returns the horse power of the car;
double getPrice() : that returns the price of the car, if the car has been sold, and 0 otherwise;
String getOwner() : that returns the name of the owner of the car, if the car has been sold, and null otherwise;
boolean isSold() : that checks whether the car has been sold;
void sell(String n, double p) : that changes the status of the car to sold, by setting the name of the owner of the car to n and the price to p; if the car had already been sold, the method should do nothing;
String toString() : that returns a string with all the information about the car.

Example program: TestCar.Java

Part 2. Write a class UseCar, client of Car, that contains the following public static method:

static double averagePriceSold(Car[] ar) : that, given an archive ar of cars, represented as an array of cars, calculates the average price of the cars that have been sold. If there are no cars that have been sold in the archive, the method should return 0.