USER-DEFINED CLASSES AND ADTS - Java Programming: From Problem Analysis to Program Design - page 497

public String toString()
{

return String.format("Radius = %.2f, Perimeter = %.2f"
+ ", Area = %.2f%n", radius, perimeter(),
area());

}

}
We leave the UML class diagram of the class Circle as an exercise for you.
The following program shows how to use the class Circle in a program.
// Program to test various operations of the class Circle.

import java.util.*; //Line 1

public class TestProgCircle //Line 2

{ //Line 3

static Scanner console = new Scanner(System.in); //Line 4

public static void main(String[] args) //Line 5

{ //Line 6

Circle firstCircle = new Circle(); //Line 7

Circle secondCircle = new Circle(12); //Line 8

double radius; //Line 9

8

System.out.println("Line 10: firstCircle: "
+ firstCircle); //Line 10

System.out.println("Line 11: secondCircle: "
+ secondCircle); //Line 11

System.out.print("Line 12: Enter the radius: "); //Line 12
radius = console.nextDouble();

//Line 13

System.out.println(); //Line 14

firstCircle.setRadius(radius); //Line 15

System.out.println("Line 16: firstCircle: "
+ firstCircle ); //Line 16

if (firstCircle.getRadius()
> secondCircle.getRadius())

//Line 17

System.out.println("Line 18: The radius of "
+ "the first circle is greater than "
+ "the radius of the second circle. "); //Line 18
else if (firstCircle.getRadius()
< secondCircle.getRadius()) //Line 19

System.out.println("Line 20: The radius of "
+ "the first circle is less than the "
+ "radius of the second circle. ");

//Line 20