ex9_02.cpp

Beginning Visual C++ 6源码。Wrox。

// EX9_02.CPP
// Using a destructor to free memory
#include <iostream>               // For stream I/O
#include <cstring>                // For strlen() and strcpy()
using namespace std;

class CMessage
{
   private:
      char* pmessage;                   // Pointer to object text string                                                            
   
   public:

      // Function to display a message
      void ShowIt() const
      {
         cout << endl << pmessage;
      }

      // Constructor definition
      CMessage(const char* text = "Default message")
      {
         pmessage = new char[strlen(text) + 1];   // Allocate space for text
         strcpy(pmessage, text);                  // Copy text to new memory
      }

      ~CMessage();                                // Destructor prototype
};

// Destructor to free memory allocated by new
CMessage::~CMessage()
{
   cout << "Destructor called."       // Just to track what happens
        << endl;
   delete[] pmessage;                 // Free memory assigned to pointer
}

int main()
{
   // Declare object
   CMessage motto("A miss is as good as a mile.");

   // Dynamic object
   CMessage* pM = new CMessage("A cat can look at a queen.");

   motto.ShowIt();                // Display 1st message
   pM->ShowIt();                  // Display 2nd message
   cout << endl;

   // delete pM;                  // Manually delete object created with new
   return 0;
}