ex9_11.cpp

Visual C++ 2005的源代码

// Ex9_11.cpp
// Using an abstract class with multiple levels of inheritance
#include "Box.h"                 // For CBox and CContainer
#include "Can.h"                 // For CCan (and CContainer)
#include "GlassBox.h"            // For CGlassBox (and CBox and CContainer)
#include <iostream>              // For stream I/O
using std::cout;
using std::endl;

const double PI = 3.14159265;                // Global definition for PI

int main()
{
  // Pointer to abstract base class initialized with CBox object address
  CContainer* pC1 = new CBox(2.0, 3.0, 4.0);

  CCan myCan(6.5, 3.0);                // Define CCan object
  CGlassBox myGlassBox(2.0, 3.0, 4.0); // Define CGlassBox object

  pC1->ShowVolume();                   // Output the volume of CBox
  delete pC1;                          // Now clean up the free store

  // initialized with address of CCan object
  pC1 = &myCan;                        // Put myCan address in pointer
  pC1->ShowVolume();                   // Output the volume of CCan

  pC1 = &myGlassBox;                   // Put myGlassBox address in pointer
  pC1->ShowVolume();                   // Output the volume of CGlassBox

   cout << endl;
   return 0;
}