Week 2 - Class Example

Sports Car Example

Java program

// SportsCar: this class models a sports car.
class SportsCar {

	private String colour;		// colour of car
	private int amtGas;			// litres of gas in tank
	private int odometer;		// current odometer reading in kms
	private double fuelConsumption;	// fuel consumption in km/L

	/*
	 * SportsCar constructor: create a new sports car that has
	 *    colour 'startColour' and fuel consumption in km/L
	 *    of 'consumption.'
	 */
	public SportsCar (String startColour, double consumption) {
		colour = startColour;
		fuelConsumption = consumption;
	}

	/*
	 * fill: this method is used to fill up the car with
	 *       'fillAmount' litres of gas.
	 */
	public void fill (int fillAmount) {
		amtGas = amtGas + fillAmount;
	}

	/*
	 * drive: this method is used to drive the car for
	 *        'distance' kms.
	 */
	public void drive (int distance) {
		odometer = odometer + distance;
		amtGas = amtGas - (int)(distance/fuelConsumption);
	}

	/*
	 * report: this method prints out information about the
	 *         current state of this sports car.
	 */
	public void report () {
		System.out.println ("Colour: " + colour);
		System.out.println ("Gas: " + amtGas + " litres");
		System.out.println ("Odometer: " + odometer + " km");
		System.out.println ("Fuel Consumption: " + fuelConsumption + 
							" km/litre");
	}
}

// Drive: This program simulates the driving of two sports cars.
public class Drive {

	public static void main (String[] args) {

		// Create sports car for Dale Earnhardt.
		SportsCar earnhardt = new SportsCar ("red", 15.5);

		// Fill car with 50 litres of gas, drive 200 kms, then
		// fill with 10 more litres of gas and report state of car.
		earnhardt.fill (50);
		earnhardt.drive (200);
		earnhardt.fill (10);

		System.out.println ("Report for Earnhardt:");
		earnhardt.report();

		// ---------------------

		// Create sports car for Michael Schumacher.
		SportsCar schumacher = new SportsCar ("blue", 17.2);

		// Fill car with 40 litres of gas, drive 400 kms, and then
		// report state of car.
		schumacher.fill (40);
		schumacher.drive (400);

		System.out.println ("\nReport for Schumacher:");
		schumacher.report();
	}
}

Output

Report for Earnhardt:
Colour: red
Gas: 48 litres
Odometer: 200 km
Fuel Consumption: 15.5 km/litre

Report for Schumacher:
Colour: blue
Gas: 17 litres
Odometer: 400 km
Fuel Consumption: 17.2 km/litre