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 ;
 }