Any one who can identify the bug?? Am unable to pass the 3rd test. It is the second last project in java lesson(more on classes)

Question

import java.util.Scanner;

abstract class Shape {
int width;
abstract void area();
}
//your code goes here
public class Square extends Shape{
Square(int a){
width=a;
}
public void area(){
System.out.println(width*width);
}
}

public class Circle extends Shape{
Circle(int b){
width=b;
}
public void area(){
System.out.println(Math.PI*(width*width));
}
}

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();
b.area();
}
}

Answer 1

Don't use braces around , just use
Math.PI*width*width ;

Answer 2

In calculations, when you have double first then next all values are upcasted to double so double * int produce double value, and double * double produce double value
If you use braces, then it's just int*int=int ,next it's double * int=double, without braces it's do like double * double * double = double so first one loss some precision value but later give you accurate precision value of double value...

edit:
socka
check both values when width=11, 17
is both ways same output ? No.

Answer 3

Thanks it worked...could u explain why that was a problem

Answer 4

Thanks u...I now understand why...and no they are not producing the same output