ex9_01.cpp

Beginning Visual C++ 6源码。Wrox。

// EX9_01.CPP
// Class with an explicit destructor
#include <iostream>
using namespace std;

class CBox                     // Class definition at global scope
{
   public:
      // Destructor definition
      ~CBox()
      { cout << "Destructor called." << endl; }

      // Constructor definition
      CBox(double lv = 1.0, double bv = 1.0, double hv = 1.0):
           m_Length(lv), m_Breadth(bv), m_Height(hv)
      {
         cout << endl << "Constructor called.";
      }

      // Function to calculate the volume of a box
      double Volume() const
      {
         return m_Length*m_Breadth*m_Height;
      }

      // Function to compare two boxes which returns true
      // if the first is greater that the second, and false otherwise
      int compare(CBox* pBox) const
      {
         return this->Volume()  >  pBox->Volume();
      }

   private:
      double m_Length;         // Length of a box in inches
      double m_Breadth;        // Breadth of a box in inches
      double m_Height;         // Height of a box in inches
};

int main()
{
   CBox boxes[5];              // Array of CBox objects declared
   CBox cigar(8.0, 5.0, 1.0);  // Declare cigar box
   CBox match(2.2, 1.1, 0.5);  // Declare match box
   CBox* pB1 = &cigar;         // Initialize pointer to cigar object address
   CBox* pB2 = 0;              // Pointer to CBox initialized to null

   cout << endl 
        << "Volume of cigar is "
        << pB1->Volume();	// Volume of obj. pointed to

   pB2 = boxes;                // Set to address of array
   boxes[2] = match;           // Set 3rd element to match
   cout << endl                // Now access thru pointer
        << "Volume of boxes[2] is " << (pB2 + 2)->Volume();

   cout << endl;
   return 0;
}