– 定义一个圆类(Circle),其所在的包为bzu.info.software;定义一个圆柱类Cylinder,其所在的包为bzu.info.com;定义一个主类A,其所在的包也为bzu.info.com,在A中生成一个Cylinder对象,并输出其体积。编译并运行该类。
Circle类:
package bzu.info.software;
public class Circle {
int r;
public Circle(int r) {
this.r=r;
}
public double getarea() {
return 3.1415926*r;
}
}
Cylinder类:
package bzu.info.com;
import bzu.info.software.*;
public class Cylinder {
Circle bottom;
int height;
public Cylinder(Circle bottom, int height) {
this.bottom = bottom;
this.height = height;
}
public Cylinder(int r, int height) {
this.bottom = new Circle(r);
this.height = height;
}
public double getvolume() {
return height*bottom.getarea();
}
}
A类:
package bzu.info.com;
public class A {
public static void main(String[] args) {
Cylinder cylinder=new Cylinder(2,1);
System.out.println(cylinder.getvolume());
}
}
运行结果:
6.2831852