C++类的成员函数

#include <iostream>

using namespace std;

class Box {
   public:
      double length;         // Length of a Box
      double breadth;        // Breadth of a Box
      double height;         // Height of a Box

      // Member functions declaration
      double getVolume(void);
      void setLength( double len );
      void setBreadth( double bre );
      void setHeight( double hei );
};

// Member functions deFinitions
double Box::getVolume(void) {
   return length * breadth * height;
}

void Box::setLength( double len ) {
   length = len;
}
void Box::setBreadth( double bre ) {
   breadth = bre;
}
void Box::setHeight( double hei ) {
   height = hei;
}

// Main function for the program
int main() {
   Box Box1;                // Declare Box1 of type Box
   Box Box2;                // Declare Box2 of type Box
   double volume = 0.0;     // Store the volume of a Box here

   // Box 1 specification
   Box1.setLength(6.0); 
   Box1.setBreadth(7.0); 
   Box1.setHeight(5.0);

   // Box 2 specification
   Box2.setLength(12.0); 
   Box2.setBreadth(13.0); 
   Box2.setHeight(10.0);

   // volume of Box 1
   volume = Box1.getVolume();
   cout << Volume of Box1 :  << volume <<endl;

   // volume of Box 2
   volume = Box2.getVolume();
   cout << Volume of Box2 :  << volume <<endl;
   return 0;
}