Question

20. Explain the problem of the following classes, and then fix them:
public class Car
{
private String makeAndModel;
private String color;
public Car(String makeAndModel, String color)
{
this.color = color;
this.makeAndModel = makeAndModel;
}
public String getmakeAndModel()
{
return this.makeAndModel;
}
public String getColor()
{
return this.color;
}
}
public class HybridCar extends Car
{
private String makeAndModel;
private String color;
private String engine;
public HybridCar()
{
this.engine = "Hybrid";
this.color = "red";
this.makeAndModel = "Toyota Corolla";
}
public String getEngine()
{
return this.engine;
}
}

Answer 1

public class Car {
    private String makeAndModel;
    private String color;

    public Car(String makeAndModel, String color) {
        this.color = color;
        this.makeAndModel = makeAndModel;
    }

    public String getmakeAndModel() {
        return this.makeAndModel;
    }

    public String getColor() {
        return this.color;
    }
}

public class HybridCar extends Car {
    private String engine;
    // remove makeAndModel and color, because they are already included in Car class

    public HybridCar() {
        super("Toyota Corolla", "red"); // call super constructor with makeAndModel and color
        this.engine = "Hybrid";
    }

    public String getEngine() {
        return this.engine;
    }
}