C++实现动态绑定代码分享

#include <iostream>#include<string>using namespace std;class BookItem{private:  string bookName;  size_t cnt;public:  BookItem(const string&s,size_t c,double p):    bookName(s),cnt(c),price(p)    {}  ~BookItem(){}protected:  double price;public:  double bookPrice()  {    return this->price;  }  string getBookName()  {    return this->bookName;  }  size_t getBookCount()  {    return this->cnt;  }  virtual double money()  {     return cnt*price;  }  virtual void costMoney()  {    cout<<money()<<endl;  }};class BookBatchItem:public BookItem{private:  string bookName;  size_t cnt;public:  BookBatchItem(const string&s,size_t c,double p,double discountRate):    BookItem(s,c,p),cnt(c),discount(discountRate)    {}  ~BookBatchItem(){}private:  double discount;public:  double money()  {    if(cnt>=10)      return cnt*price*(1.0-discount);    else      return cnt*price;  }  void costMoney()  {    cout<<money()<<endl;//    cout<<cnt<<endl;//    cout<<price<<endl;//    cout<<discount<<endl;//    cout<<"..."<<endl;  }};int main(){  BookItem b1("Uncle Tom's house",11,12.5);  b1.costMoney();  BookBatchItem b2("Gone with wind",11,12.5,0.12);  b2.costMoney();  BookItem* pb=&b1;  pb->costMoney();  pb=&b2;  pb->costMoney();  return 0;}

 class Base { public:   Base() { p = new char ; }   ~Base() { delete p; } private:   char * p ; };  class Derived:public Base { public:   Derived() { d = new char[10] ; }   ~Derived() { delete[] d; } private:   char * d ; };  int main() {   Base *pA = new Derived();   delete pA ;      Derived *pA = new Derived();   delete pA ; }

 class Base { public:   virtual void Func() { cout<<"Base"<<endl; } };  class Derived:public Base { public:   virtual void Func() { cout<<"Derived"<<endl; } };  int main() {   Derived obj;   Base * p1 = &obj;   Base & p2 = obj;   Base obj2 ;    obj.Func() ;  //静态绑定，Derived的func   p1->Func();   //动态绑定，Derived的func   (*p1).Func();  //动态绑定，Derived的func   p2.Func();   //动态绑定，Derived的func   obj2.Func();  //静态绑定，Base的func    return 0 ; }