利用JAVA中关于继承的相关知识求得圆柱体体积并输出

利用JAVA中关于继承的相关知识求得圆柱体体积并输出

Write a program:

1）Define a Circle class and a Cylinder class, which is derived from the Circle and is the main class.

2）Circle class has one field: radius r, which are initialized through Circle’s constructor; one method getArea() to get the area of circle.

3）Cylinder class has one field: h, which is initialized through Cylinder’s constructor. one method getVolume() to get the of volume of cylinder.

4）In main method: output the volume of cylinder.

写程序计算圆柱体的体积：

要求：

① 定义Circle类：成员变量包括半径r，成员方法包括构造方法来初始化成员变量r，以及getArea方法用来计算面积；

② 定义Cylinder类：成员变量包括底面积（用Circle类继承得到）和高，成员方法包括构造方法来初始化成员变量（包括半径r和高h的初始化），getVolme方法用来计算圆柱体积；

③ Cylinder类作为主类，在Main方法中创建Cylinder类的对象，求得圆柱体体积并输出.、

class Circle{
	double r;
	public Circle(double r) {
		this.r=r;
	}
	public double getArea() {
		double area;
		area=3.14*r*r;
		return area;
	}
}
class Cylinder extends Circle{
	double height;
	double Area=getArea();
	public Cylinder(double r,double height) {
		super(r);
		this.height=height;
 	}
	public double getVolme() {
		double v;
		v=Area*height;
		return v;
	}
	public static void main(String[] args) {
		Cylinder hh=new Cylinder(100,10);
		System.out.println("圆柱体体积"+hh.getVolme());
}
}

运行结果：