ex1608.cpp

teach yourself C++ in 21 days 第五版

   // Bug Busters
   #include <iostream>
   using namespace std;
   class Animal;

   void setValue(Animal& , int);
   void setValue(Animal& ,int,int); // here's the change!
 
   class Animal
   {
     friend void setValue(Animal& ,int);
     friend void setValue(Animal& ,int,int);
     private:
        int itsWeight;
        int itsAge;
   };
   
   void setValue(Animal& theAnimal, int theWeight)
   {
       theAnimal.itsWeight = theWeight;
   }
    
  void setValue(Animal& theAnimal, int theWeight, int theAge)
  {
     theAnimal.itsWeight = theWeight;
     theAnimal.itsAge = theAge;
  }
     
  int main()
  {
      Animal peppy;
      setValue(peppy,5);
      setValue(peppy,7,9);
      return 0;
  }