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这是我编的图书填加的程序  但是输入一次图书 第二次出现了这种情况看下运行图片http://images.51.com/d/200611/0c/a2/qing878/6f188483be7da584f760ce5b59376975.jpg 谁解释下
#include "iostream"
using namespace std;
class BOOK{
      private:
      string name;
      string author;
      string state;
      int ID;
      int price;
      public:
      BOOK()
      {
            name="null";
            author=" ";
            state="在馆";
            price=0;
            }
void addbook()
{    
      ID=0;
      ID++;
     for(int i=0;i<2;i++)
     {
           if(name=="null")
             {
             cout<<"请输入书名:";
             cin>>name;
             cout<<"请输入作者:";
             cin>>author;
             cout<<"请输入书价格:";
             cin>>price;
             break;}
             }
             }
             void sharebook()
             {
                   cout<                   cout<                   cout<                   cout<                   }
            };
int main()
{  
    BOOK book[2];
    for(int j=0;j<2;j++)
    {    
    book[j].addbook();
}
    cout<<"书号"<<"\t";
    cout<<"书名"<<"\t";
    cout<<"作者"<<"\t";
    cout<<"价格"<<"\t"<    for(int i=0;i<2;i++)
    {
   
    book[i].sharebook();
}
    system("pause");
}

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