把这三个类分别放到三个.java文件中,然后编译运行即可.
public class Circle{
private double r;
public Circle(double r){
this.r = r;
}
public double getZhou(){
return 2*Math.PI*r;
}
public double getArea(){
return Math.PI*r*r;
}
public void setR(double r){
this.r = r;
}
public int getR(){
return r;
}
}
public class Cylinder extends Circle{
private double h;
public Cylinder(double r, double h){
super(r);
this.h = h;
}
public double getFaceArea(){
getZhou() * h;
}
public double getVolumn(){
getArea() * h;
}
public void setH(double h){
this.h = h;
}
public int getH(){
return h;
}
}
public class mainClass{
public static void main(String[] args){
Circle c = new Circle(2);
Cylinder cy = new Cylinder(3,5);
System.out.println("半径为"+c.getR()+"的圆"+"周长为"+c.getZhou()+",面积为"+c.getArea());
System.out.println("半径为"+cr.getR()+",高为"+cr.getH()+"的圆柱"+"表面积为"+cr.getFaceArea()+",体积为"+cr.getVolumn());)
}
}
