c9-4.cpp

这我们老师对是面向对象程序设计（清华大学出版社）一书制作的PPT

#include <iostream>
using namespace std;
class Box
 {public:
   Box(int w=10,int h=10,int len=10);
   int volume();
  private:
   int height;
   int width;
   int length;
 };

Box::Box(int w,int h,int len)
 {height=h;
  width=w;
  length=len;
 }

int Box::volume()
 {return(height*width*length);
 }
 
    
int main()
 {
  Box box1;
  cout<<"The volume of box1 is "<<box1.volume()<<endl;
  Box box2(15);
  cout<<"The volume of box2 is "<<box2.volume()<<endl;
  Box box3(15,30);
  cout<<"The volume of box3 is "<<box3.volume()<<endl;
  Box box4(15,30,20);
  cout<<"The volume of box4 is "<<box4.volume()<<endl;
  return 0;
 }