ex7_05.cpp

Visual C++ 2005的源代码

// Ex7_05.cpp
// Supplying and using a default constructor
#include <iostream >
using std::cout;
using std::endl;

class CBox                             // Class definition at global scope
{
  public:
    double m_Length;                   // Length of a box in inches
    double m_Width;                    // Width of a box in inches
    double m_Height;                   // Height of a box in inches

    // Constructor definition
    CBox(double lv, double bv, double hv)  
    {
      cout << endl << "Constructor called.";
      m_Length = lv;                   // Set values of
      m_Width = bv;                    // data members
      m_Height = hv;
    }

    // Default constructor definition
    CBox()
    { 
      cout << endl << "Default constructor called.";
    }

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

int main()
{
  CBox box1(78.0,24.0,18.0);           // Declare and initialize box1
  CBox box2;                           // Declare box2 - no initial values
  CBox cigarBox(8.0, 5.0, 1.0);        // Declare and initialize cigarBox

  double boxVolume = 0.0;              // Stores the volume of a box

  boxVolume = box1.Volume();           // Calculate volume of box1
  cout << endl
       << "Volume of box1 = " << boxVolume;

  box2.m_Height = box1.m_Height - 10;  // Define box2
  box2.m_Length = box1.m_Length / 2.0; // members in
  box2.m_Width = 0.25*box1.m_Length;   // terms of box1

  cout << endl
       << "Volume of box2 = "
       << box2.Volume();

  cout << endl
        << "Volume of cigarBox = "
        << cigarBox.Volume();

  cout << endl;
  return 0;
}