Question

I want to write a superclass with one private attribute and one method in JAVA

The super class will later derive into 2 subclasses each with its own private attributes and each with a method that OVERRIDES the superclass method with each subclasses with one method ( that will do something) unique to that subclass. ALL classes must have constructors initializing its attributes and getter/setter methods. Then, in the main method,  keep initializing objects of type superclasses based on user's choice and add them to the ArrayList.

Answer 1

Program

import java.io.IOException;
import java.util.ArrayList;

class Car{//super class
   private int price;
  
   public Car(int price) {
       this.price = price;
   }
   public int getPrice() {
       return price;
   }
   public void setPrice(int price) {
       this.price = price;
   }
   public double SalesPrice() {
       double totalPrice = price * 0.1;// 10% discount
       return price-totalPrice;
   }
}

class MVP extends Car{
   private int length;
  
   public MVP(int price, int length) {
       super(price);
       this.length = length;
   }

   @Override
   public double SalesPrice() {//calculating the sales price
       double discountPrice;
       if(length>15) {
           discountPrice = getPrice() * 0.025;//2.5% discount
       }
       else {
           discountPrice = getPrice() * 0.05;//5% discount
       }
       return getPrice() - discountPrice;
   }
}

class Sedan extends Car{
   private int manufacturerDiscount;
  
   public Sedan(int price, int manufacturerDiscount) {
       super(price);
       this.manufacturerDiscount = manufacturerDiscount;
   }

   @Override
   public double SalesPrice() {//deducting manufacturer discount
       double totalPrice = super.SalesPrice() - manufacturerDiscount;
       return totalPrice;
   }
}

public class KuchBhi {// driver class
   public static void main(String[] args)throws IOException {// driver method
       ArrayList<Car> ar = new ArrayList<>();
       //adding objects of subclasses
       ar.add(new MVP(1500, 20));
       ar.add(new Sedan(3000, 750));
       //showing result
       System.out.println("MVP Sales Price: "+ar.get(0).SalesPrice());
       System.out.println("Sedan Sales Price: "+ar.get(1).SalesPrice());
   }
}

Program Screenshot

KuchBhi.java 1 import java.io.IOException; 2 import java.uti1.ArrayList; 4 class Car//super class private int price; 7 public Car(int price) f this.priceprice; 10 public int getPrice() return price; 12 13 14 15 16 public void setPrice(int price) { this, price = price; public double SalesPrice() ( double totalPrice-price * 0.1;// 10% discount return price-totalPrice; 18 19 20 21 22 class MVP extends Car 23 24 25 public MVP (int price, int length) 26 27 28 29 30 override 31 public double SalesPrice) (//calculating the sales price 32 private int length; super (price); this.length length; double discountPrice; if(length>15) f discountPrice getPrice() * 0.025;//2.5% discount 34 35 36 37 38 39 40 else discountPrice- getPrice() * 9.05;//5% discount return getPrice) - discountPrice; 43 class Sedan extends Cart private int manufacturerDiscount; 45 46 public Sedan(int price, int manufacturerDiscount) 47 48 super (price); this.manufacturerDiscount manufacturerDiscount; 50 510verride 52 public double SalesPrice() (//deducting manufacturer discount 53 54 double totalPricesuper.SalesPrice) manufacturerDiscount; return totalPrice; 56 58 public class KuchBhi // driver class 59 public static void main(String[] args)throws IOException// driver method 60 61 62 ArrayList ar new ArrayList<); //adding objects of subclasses ar.add (new MVP (1500, 20)); Page 1

KuchBhi.java 63 64 65 ar.add(new Sedan (3000, 750)); //showing result System.out.println("MVP Sales Price: "+ar.get (ø).SalesPrice()); System.out.println("Sedan Sales Price: "+ar.get (1).SalesPrice)); 67 68

Output

KuchBhi (1) Java Application] C:Program FilesJava jre1.8.0_181 bin javaw.exe (08-Apr-2019, 3:01:21 PM) MVP Sales Price: 1462.5 Sedan Sales Price: 1950.0