Question

PLEASE CODE THIS IN JAVA

Create a driver class Playground that contains the function, public static void main(String[] args) {}.

• Create 2 SportsCar and 2 Airplane instances using their constructors. (SPORTSCAR AND AIRPLANE CLASSES LISTED BELOW THIS QUESTION.
• Add all 4 instances into a single array called, “elements.”
• Create a loop that examines each element in the array, “elements.” If the elements item is a SportsCar, run the sound method and if the item is an Aeroplane, run it’s ChangeSpeed method.
• Run the getCount() method (GET COUNT METHOD SHOWN IN CAR CLASS BELOW THIS QUESTION) to display how many total cars were created.

SportsCar Class:

class SportsCar extends Car{
   private String roof;
   private int doors;
   public SportsCar(String r,int d,String m) {
       super(0,m);
       roof=r;
       doors=d;
   }
   public void ChangeSpeed() {
       speed+=20;
       if(speed>65) {
           throw new IllegalArgumentException("Invalid Speed");
       }
      
   }
   public void sound() {
       System.out.println("broooom");
   }
   @Override
   public void Start() {
      
   }
   @Override
   public void Stop() {
   }
}

Airplane Class:

//Airplane.java
public class Airplane implements Vehicle{

    int speed;

    public Airplane() {
        this.speed = 0;
    }

    public void Start() {
        System.out.println("Start method called");
    }

    public void Stop() {
        System.out.println("Stop method called");
    }

    public void ChangeSpeed() {
        speed += 5;
    }

    public int getSpeed() {
        return speed;
    }

    public void setSpeed(int speed) {
        this.speed = speed;
    }
}

Car Class:

interface Vehicle{
        void Start();
        void Stop();
        void ChangeSpeed();
}
abstract class Car implements Vehicle{
        private int year;
        private int speed;
        private String make;
        private static int count=0;
        public Car(int aYear, String aMake) {
                year = aYear;
                make = aMake;
                speed=0;
                count++;
        }
        abstract void sound();
        public static int getCount() {
                return count;
        }
        
}

Answer 1

class SportsCar extends Car{
   private String roof;
   private int doors;
   public SportsCar(String r,int d,String m) {
       super(0,m);
       roof=r;
       doors=d;
   }
   public void ChangeSpeed() {
       speed+=20;
       if(speed>65) {
           throw new IllegalArgumentException("Invalid Speed");
       }
      
   }
   public void sound() {
       System.out.println("broooom");
   }
   @Override
   public void Start() {
      
   }
   @Override
   public void Stop() {
   }
}
 class Airplane implements Vehicle{

    int speed;

    public Airplane() {
        this.speed = 0;
    }

    public void Start() {
        System.out.println("Start method called");
    }

    public void Stop() {
        System.out.println("Stop method called");
    }

    public void ChangeSpeed() {
        speed += 5;
    }

    public int getSpeed() {
        return speed;
    }

    public void setSpeed(int speed) {
        this.speed = speed;
    }
}
interface Vehicle{
        void Start();
        void Stop();
        void ChangeSpeed();
}
abstract class Car implements Vehicle{
        private int year;
        public int speed;
        private String make;
        private static int count=0;
        public Car(int aYear, String aMake) {
                year = aYear;
                make = aMake;
                speed=0;
                count++;
        }
        abstract void sound();
        public static int getCount() {
                return count;
        }
        
}
public class Playground {
        public static void main(String args[]) {
                SportsCar car1 = new SportsCar("Roof1",1000,"Door1");
                SportsCar car2 = new SportsCar("Roof1",1000,"Door1");
                Airplane plane1 = new Airplane();
                Airplane plane2 = new Airplane();
                String elements[]= {"car1","car2","plane1","plane2"};
                for(int i = 0; i < elements.length; i++) {
                        if(elements[i] == "car1") {
                                car1.sound();
                        }
            else if(elements[i] == "car2") {
                 car2.sound();
            }
            else if(elements[i] == "plane1") {
                  plane1.ChangeSpeed();
            }
            else if (elements[i] == "plane2"){
                  plane2.ChangeSpeed();
            }
           Car.getCount();
                }
   }
}