定义一个Dog类，包括体重和年龄两个数据成员及其成员函数，声明一个实例dog1，体重5，年龄10，使用I/O流把dog1的状态写入磁盘文件。再声明一个实例dog2，通过读取文件dog1的状态赋给dog

#include<bits/stdc++.h>

using namespace std;

class Dog

{

       private:

              int weight,age;

       public:

              Dog(int w,int a):weight(w),age(a)

              {

              }

              int getw()

              {

                     return weight;

              }

              int geta()

              {

                     return age;

              }

};

int main()

{

       Dog dog3(5,10);

       fstream out1;

       out1.open("dog3.txt",ios::binary|ios::out);

       out1<<"体重："<<dog3.getw()<<endl<<"年龄："<<dog3.geta()<<endl;

       fstream in,out2;

       in.open("dog3.txt",ios::binary|ios::in);.

       out2.open("dog4.txt",ios::binary|ios::out);

       out2<<"dog4=dog3"<<endl;

       char ch;

       while(!in.eof())

       {

              in.get(ch);

              out2.put(ch);

       }

       return 0;

}