v-overload.cpp

适合初学者学习以及程序员回顾

// V-Overload.cpp

#include <iostream>
using std::cin;
using std::cout;
using std::endl;

//---- 宣告类别 Shape --------
class Shape
{
private:
  int i;
public:
  Shape(): i(7){}
  ~Shape(){}
  virtual void Rotate()   {cout<<"将图回转 \n";}
  virtual void Rotate(int N)
    {cout<<"将图回转 "<< N << " 单位\n";}
  virtual void Erase()  {cout<<"将图清除\n";}
};

//---- 宣告类别 Circle--------
class Circle : public Shape
{
private:
  int r;
public:
  Circle(): r(5)      {}
  Circle(int N): r(N) {}
  ~Circle()           {}
  void Rotate()  {cout<<"将圆形回转\n";}
  void Erase()   {cout<<"把圆形清除 \n";}
};

//---- 宣告类别 Cylinder--------
class Cylinder : public Circle
{
private:
  int r, h;
public:
  Cylinder(): r(5), h(1)    {}
  Cylinder(int M, int N): r(M), h(N) {}
  ~Cylinder()         {}
  void Rotate(){cout<<"将圆柱形回转\n";}
  void Erase() {cout<<"把圆柱形清除 \n";}
};

// ----主程式---------------------------
main()
{
  Circle C1;
  Cylinder CyL;
  Shape *pS = &C1;
  Shape &S1 = CyL;
  cout << "“pS->Rotate()” : ";
  pS->Rotate();
  cout << "“pS->Rotate(2)”: ";
  pS->Rotate(2);
  cout << "“ S1.Rotate()” : ";
  S1.Rotate();
  cout << "“ S1.Rotate(4)”: ";
  S1.Rotate(4);
}