Circle派生出Cylinder类

程序代码

#include <iostream>

using namespace std;

class Point//点类
{
public:
    //使用初始化表初始化点类
    Point(double a = 0, double b = 0):x(a), y(b){}
    void setPoint(double a, double b);//设置点的坐标
    double getX();
    double getY();

    //重载<<实现点的坐标的输出
    friend ostream& operator<<(ostream &output, Point &p);

protected:
    double x;//横坐标
    double y;//纵坐标
};

//设置点的坐标
void Point::setPoint(double a, double b)
{
    x = a;
    y = b;
}

//得到x的值
double Point::getX()
{
    return x;
}

//得到y的值
double Point::getY()
{
    return y;
}

//重载<<实现点的坐标的输出
ostream& operator<<(ostream &output, Point &p)
{
    output<<"("<<p.x<<","<<p.y<<")"<<endl;

    return output;
}


//Point派生出Circle类
class Circle : public Point
{
public:
    //构造函数(初始化半径的两个端点)
    Circle(double a, double b, double r);
   void SetRadius(double r);//设置圆的半径
   double GetRadius();//得到圆的半径
   double getArea();//计算圆的面积
  
   //重载<<实现输出圆的面积
  friend ostream& operator<<(ostream &output, Circle &c);

protected:
    double r;//圆的半径
};

//构造函数(使用初始化表初始化Circle类)
Circle::Circle(double a, double b, double r): Point(a, b), r(r){}


//设置圆的半径
void Circle::SetRadius(double r)
{
    this->r = r;
}

//得到圆的半径
double Circle::GetRadius()
{
    return r;
}

//计算圆的面积
double Circle::getArea()
{
    //计算圆的面积
    double s = 3.14 * r * r;

    return s;
}

//重载<<输出圆的面积
ostream& operator<<(ostream &output, Circle &c)
{
    output<<"圆的面积:"<<c.getArea()<<endl;

    return output;
}

//圆类派生出圆柱类
class Cylinder : public Circle
{
public:
    Cylinder(double a = 0, double b = 0, double r = 0, double h = 0);//构造函数  
    void setHeight(double h);//设置圆柱体的高度
    double SuperArea();//计算圆柱体的表面积
    double setVolume();//计算圆柱体的的体积
 
    //重载<<实现输出圆柱体的表面积和体积
  friend ostream& operator<<(ostream &output, Cylinder &cy);

protected:
    double height;//高度
};

//构造函数
 Cylinder::Cylinder(double a, double b, double r, double h):
 Circle(a, b, r), height(h){}


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

//计算圆柱体的表面积
double Cylinder::SuperArea()
{
    double s;

    s = 2 * Circle::getArea() + 2 * 3.14 * Circle::GetRadius() * height;

    return s;
}

//计算圆柱体的的体积
double Cylinder::setVolume()
{
    double v;

    v = Circle::getArea() * height;

    return v;
}

//重载<<实现输出圆柱体的表面积和体积
ostream& operator<<(ostream &output, Cylinder &cy)
{
    output<<"圆柱体的表面积:"<<cy.SuperArea()<<"\n"<<"圆柱体的体积:"<<cy.setVolume()<<endl;

    return output;
}

 void main()
{
    //定义一个圆柱体对象
    Cylinder c1;

    //设置点的坐标
    c1.setPoint(1.0, 2.0);

    //设置圆的半径
    c1.SetRadius(2.0);

    //设置圆柱体的高为1.0
    c1.setHeight(1.0);

    //输出圆柱体的表面积和体积
    cout<<c1;

    system("pause");
}

执行结果