staticfunction.cpp

24学时攻克C++光盘源代码 深入浅出 方便实用

 //Listing 20.2 static data members
 #include <iostream>
 
 class Cat
 {
 public:
     Cat(int age = 1):itsAge(age){HowManyCats++; }
     virtual ~Cat() { HowManyCats--; }
     virtual int GetAge() { return itsAge; }
     virtual void SetAge(int age) { itsAge = age; }
     static int GetHowMany() { return HowManyCats; }
 private:
     int itsAge;
     static int HowManyCats;
 };
 
 int Cat::HowManyCats = 0;
 
 void TelepathicFunction();
 
 int main()
 {
     const int MaxCats = 5;
     Cat *CatHouse[MaxCats];
     int i;
     for (i = 0; i<MaxCats; i++)
     {
         CatHouse[i] = new Cat(i);
         TelepathicFunction();
     }
 
     for ( i = 0; i<MaxCats; i++)
     {
         delete CatHouse[i];
         TelepathicFunction();
     }
     return 0;
 }
 
 void TelepathicFunction()
 {
     std::cout << "There are " << Cat::GetHowMany()
         << " cats alive!\n";
 }