derivedobject.cpp

来自「《24学时精通c++》的光盘内容」· C++ 代码 · 共 56 行

 //Listing 16.2 Using a derived object
 #include <iostream>
 
 enum BREED { YORKIE, CAIRN, DANDIE, SHETLAND, DOBERMAN, LAB };
 
 class Mammal
 {
 public:
     // constructors
     Mammal():itsAge(2), itsWeight(5){}
     ~Mammal(){}
 
     //accessors
     int GetAge()const { return itsAge; }
     void SetAge(int age) { itsAge = age; }
     int GetWeight() const { return itsWeight; }
     void SetWeight(int weight) { itsWeight = weight; }
 
     //Other methods
     void Speak()const { std::cout << "Mammal sound!\n"; }
     void Sleep()const { std::cout << "shhh. I'm sleeping.\n"; }
 
 
 protected:
     int itsAge;
     int itsWeight;
 };
 
 class Dog : public Mammal
 {
 public:
     // Constructors
     Dog():itsBreed(YORKIE){}
     ~Dog(){}
 
     // Accessors
     BREED GetBreed() const { return itsBreed; }
     void SetBreed(BREED breed) { itsBreed = breed; }
 
     // Other methods
     void WagTail() { std::cout << "Tail wagging...\n"; }
     void BegForFood() { std::cout << "Begging for food...\n"; }
 
 private:
     BREED itsBreed;
 };
 
 int main()
 {
     Dog fido;
     fido.Speak();
     fido.WagTail();
     std::cout << "Fido is " << fido.GetAge() << " years old\n";
     return 0;
 }