Exercise: Car

Car Simulation

Write Car class. A car is defined by:

How much petrol the car can hold:

int maxFuel

How much petrol is left:

int fuelLeft

How much petrol is used per kilometer:

int fuelPerKilometer

A car is constructed with how much fuel it can hold and how much fuelPerKilometer it uses:

Car(int maxFuel, int fuelPerKilometer)

A car can be refueled. The method accepts how much to refuel and returns how much more fuel is needed until the tank is full. It returns a negative number if the tank overflows. The fuel goes into the tank, but the tank can not become more full than maxFuel.

int refuel(int liters)

Driving uses fuel from the tank. How much fuel is used is defined by fuelPerKilometer. The tank must never become more than empty < 0

void drive(int kilometers)

To check how much fuel is left in the tank the following method needs to be implemented:

int getFuelLeft()

Use the following main class to check your code:

import org.redischool.introjava.Car;

public class Main {

    public static void main(String[] args) {
        int tankSize = 10;

        Car car = new Car(tankSize, 1);
        int left = car.refuel(3);
        left = car.refuel(left);
        if (left != 0) {
            System.out.println("ERROR: refuel method is wrong.");
            System.out.printf("|- Expected: %d, Got: %d\n", 0, left);
            return;
        }

        car.drive(4);
        car.drive(2);

        left = car.getFuelLeft();
        if (left != 4) {
            System.out.println("ERROR: drive org getFuelLeft method is wrong.");
            System.out.printf("|- Expected: %d, Got: %d\n", 4, car.getFuelLeft());
            return;
        }

        left = car.refuel(100);
        if (left != -94) {
            System.out.println("ERROR: refuel method is wrong.");
            System.out.printf("|- Expected: %d, Got: %d\n", -94, left);
            return;
        }

        left = car.getFuelLeft();
        if (left != tankSize) {
            System.out.println("ERROR: refuel or getFuelLeft method is wrong.");
            System.out.printf("|- Expected: %d, Got: %d\n", tankSize, left);
            return;
        }

        car.drive(100);
        left = car.getFuelLeft();
        if (left != 0) {
            System.out.println("ERROR: drive or getFuelLeft method is wrong.");
            System.out.printf("|- Expected: %d, Got: %d\n", 0, left);
            return;
        }

    }
}