Can anyone please tell, What mistak I had done here?

Question

import java.util.Scanner;

abstract class Shape {
int width;
abstract void area();
}
//your code goes here

class Square extends Shape {
public Square(int w) {
width = w;
}
public void area(){
//width = w
width *= width;
System.out.println(width);
}
}
class Circle extends Shape {
public Circle(int w) {
width = w;
}
public void area(){
//width = w
double PI = Math.PI;
double areaCircle = (double) width * width * PI;
System.out.println(areaCircle);
}
}

public class Program {
public static void main(String[ ] args) {
Scanner sc = new Scanner(System.in);
int x = sc.nextInt();
int y = sc.nextInt();
Square a = new Square(x);
Circle b = new Circle(y);
a area(x);
b area(y);
}
}

Answer 1

abstract method is declared without parameters. but in a.area(x) you passed x.
so change it in Shape class and define it in the extended classes.

abstract void area(int w) ;

public void area(int w){
width = w;
}
a.area(x);
b.area(y);

Answer 2

Then what should I do

Answer 3

Can you please share code here

Answer 4

Since you want to polymorphic ally program your classes, I will first advice you to

1. You are to store the object of the subclasses to the variables of it's super class in this case the abstract class...
Let me demonstrate these concepts for you..

abstract class Shapes{

int width;

abstract void area();

}//abstract class declaration

class Square extends Shapes {

public Square (int w) {

width = w;
//your constructor here

//method area
public void area(){

width = width * width;

}//Subclass declaration

//Main methods

public class program {
public static void main (String[] args){

//To polymorphically process their methods..u do this

Shapes[] shape = new Shapes();//these creates arrays of superclass to keep the object of subclasses

shape[ 0] = new Square(2);//2 is your width
shape[ 1] = new Circle(3);//3 is your width

//So to access the area methods
//in any of those classes..
//Use this.

for(Shapes currentShape : shape)
{
System.out.println (currentShape);
}

Answer 5

Ok I'll try

Answer 6

It will be more easy to understand.

Answer 7

or you can keep it the way it is.
just don't pass x and y to area()
since they are passed to the constructor
should use
a.area();
b.area();
you're missing a dot between objects and method.

Answer 8

Means

Answer 9

I really don't understand what you said

Answer 10

Thanks Bahha

Answer 11

Thanks Ibidunni Ridwan🙏

Answer 12

Thanks

Answer 13

your code modified normally the constructor is enough, so the area does not have to be modified.

Answer 14

this code is hella wrong the ( PrintIn ) is used for “ private static void “.

Answer 15

Bonsoir