例4-7.txt

这是一本java基础教程 对新手上路有很大帮助

class Circle{
    double radius;
    Circle(double r){
       radius=r;
    }
    double computerArea(){
       return 3.14*radius*radius;
    }
    void setRadius(double newRadius){
       radius=newRadius;
    }
    double getRadius(){
       return radius;
    }
}
class Cone{
    Circle bottom;
    double height;
    Cone(Circle c,double h){
       bottom=c;
       height=h;
    }
    double computerVolume(){ 
       double volume;
       volume=bottom.computerArea()*height/3.0;
       return volume;
    }
    void setBottomRadius(double r){
       bottom.setRadius(r);
    }
    double getBottomRadius(){
       return bottom.getRadius();
    }
}
public class Example4_7{
    public static void main(String args[]){
       Circle circle=new Circle(8);
       Cone circular=new Cone(circle,18);
       System.out.println("circular的bottom半径:"+circular.getBottomRadius()); 
       System.out.println("circular的体积:"+circular.computerVolume());
       circular.setBottomRadius(88);
       System.out.println("circular的bottom半径:"+circular.getBottomRadius());
       System.out.println("circular的体积:"+circular.computerVolume());  
    }
}