1 class Cylinder {
2 private double radius;
3 private int height;
4 private double pi=3.14;
5 String color;
6 public Cylinder() {
7 this(2.5,5,"红色");
8 System.out.println("无参构造方法被调用了");
9 }
10 public Cylinder(double r,int h,String str) {
11 System.out.println("有参构造方法被调用了");
12 radius=r; height=h;color=str;
13 }
14 double area() {
15 return pi*radius*radius;
16 }
17 double volume() {
18 return area()*height;
19 }
20 }
21 public class C1_6 {
22 public static void main(String[] args) {
23 Cylinder volu=new Cylinder();
24 System.out.println("底面积为: "+volu.area());
25 System.out.println("体积为: "+volu.volume());
26 }
27 }
