cylinder2.cpp

用三个类来研究类的继承！类Point、Circle、Cylinder

//cylinder2.cpp
//类Cylinder的成员函数和友元函数的定义
#include <iostream.h>
#include <assert.h>
#include <iomanip.h>
#include "point2.h"
#include "circle2.h"
#include "cylinder2.h"

//构造函数：用成员初始化表初始化圆柱体的底圆，并初始化其高
Cylinder:: Cylinder(float h, float r, float a, float b)
 :Circle(r, a, b)	//调用基类的构造函数初始化圆柱体的底圆
{	
	height=h;	//圆柱体的高
}

//设置圆柱体的高度
void Cylinder::setHeight(float h)
{
	height=h;
}

//返回圆柱体的高
float Cylinder:: getHeight() const {return height;}

//计算并返回圆柱体的表面积
float Cylinder:: area() const
{
	return (2*Circle:: area()+2*3.14159*radius*height);
}

//计算并返回圆柱体的体积
float Cylinder:: volume() const
{
	return (Circle:: area()*height);
}

//输出圆柱体的尺寸
ostream &operator<< (ostream &output, const Cylinder &c)
{
	output<<"Center=["<<c.x<<", "<<c.y<<"]; Radius"<<setiosflags(ios:: showpoint)
		<<setprecision(3)<<c.radius<<"; Height"<<c.height;

	return output;	//使得能够连续输出88
}