Question

Answer the following:

1.        Create a Class Car with the following instance variables: model (String), Brand

(String), maxspeed (double) Note: use encapsulation (all variables are private). (3 Marks)

2.        Create a non-default constructor for Class Car which takes 3 parameters. (2 Marks)

3.        Create a get and set methods for instance variable model variable only. (2 Marks)

4.        Create PrintInfo() method which prints all three instance variables. (2 Marks)

5.        Create a subclass GasCar with instance variable TankSize (double).. (2 Marks)

6.        Create a non-default constructor for sub-class GasCar which takes 4 parameters. (2 Marks)

7.        Override PrintInfo() method which prints all four parameters. (2 Marks)

8.        Create a subclass ElectricCar with instance variable BatteryPower (double). (2 Marks)

9.        Create a non-default constructor for sub-class ElectricCar which takes 4 parameters. (2 Marks)

10.    Override PrintInfo() method which prints all four parameters. (2 Marks)

11. Using the Car, Gas, and Electrical classes create a java application program which demonstrate the polymorphism principles in Java as following:

Write the main program by creating two references of type Car and the objects of type GasCar and ElectricCar.

Call PrintInfo method for both objects. (4 Marks)

Answer 1

public class Car{

    // Create a Class Car with the following instance variables: model (String), Brand

    //(String), maxspeed (double) Note: use encapsulation (all variables are private).

    private String model;

    private String brand;

    private double maxSpeed;

    //Create a non-default constructor for Class Car which takes 3 parameters.

    public Car(String model, String brand, double speed){

        this.model=model;

        this.brand=brand;

        this.maxSpeed=speed;

    }

    //3.        Create a get and set methods for instance variable model variable

    public String getModel() {

        return model;

    }

    //3.        Create a get and set methods for instance variable model variable

    public void setModel(String model) {

        this.model = model;

    }