public class TestCircle1 {

  /** Main method */

  public static void main(String[] args) {

    // Create a circle with radius 5.0
    Circle1 myCircle = new Circle1(5.0);

    System.out.println("The area of the circle of radius "

      + myCircle.radius + " is " + myCircle.getArea());



    // Create a circle with radius 1
    Circle1 yourCircle = new Circle1();

    System.out.println("The area of the circle of radius "

      + yourCircle.radius + " is " + yourCircle.getArea());



    // Modify circle radius
    yourCircle.radius = 100;

    System.out.println("The area of the circle of radius "

      + yourCircle.radius + " is " + yourCircle.getArea());

  }

}



// Define the circle class with two constructors
class Circle1 {

  double radius;



  /** Construct a circle with radius 1 */

  Circle1() {

    radius = 1.0;

  }



  /** Construct a circle with a specified radius */

  Circle1(double newRadius) {

    radius = newRadius;

  }



  /** Return the area of this circle */

  double getArea() {

    return radius * radius * Math.PI;

  }

}