frisq.cpp

来自「本课程主要介绍面向对象程序设计的方法和c++语言的基本概念。以c++语言中的面向」· C++ 代码 · 共 41 行

// frisq.cpp
// friend square() function for Distance
#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////
class Distance                    //English Distance class
   {
   private:
      int feet;
      float inches;
   public:
      Distance() : feet(0), inches(0.0) //constructor (no args)
         {  }
                                        //constructor (two args)
      Distance(int ft, float in) : feet(ft), inches(in)  
         {  }
      void showdist()                   //display distance
         { cout << feet << "\'-" << inches << '\"'; }
      friend float square(Distance);    //friend function
   };
//--------------------------------------------------------------
float square(Distance d)          //return square of
   {                              //this Distance
   float fltfeet = d.feet + d.inches/12;  //convert to float
   float feetsqrd = fltfeet * fltfeet;    //find the square
   return feetsqrd;               //return square feet
   }
////////////////////////////////////////////////////////////////
int main()
   {
   Distance dist(3, 6.0);         //two-arg constructor (3'-6")
   float sqft;

   sqft = square(dist);           //return square of dist
                                  //display distance and square
   cout << "\nDistance = "; dist.showdist();
   cout << "\nSquare = " << sqft << " square feet\n";
   return 0;
   }