例题4-2

class Circle{
 double radius;
 double getArea(){
  double area=3.14*radius*radius;
  return area;
 }
}
 
public class Example4_2{
 public static void main (String args[]){
  Circle circle;
  circle=new Circle();
  circle.radius=163.16;
  double area=circle.getArea();
  System.out.printf("半径是%5.3f的圆的面积:\n%5.3f\n",circle.radius,area);
 }
}