这个人员类有什么问题 怎么解决

赞成楼上的观点，改到一半实在改不下去了……

我也是新手，不过确实有好多问题啊，尝试着改了下，互相学习吧：（ 问题可真的不少，建议楼主先编点简单的，还有可以考虑好好看看构造函数是怎么用的，还有构造函数的重载问题。）

#include<iostream>
using namespace std;

// define class of Birthday
class Birthday
{
        int Year;   //C++默认私有变量，不需要private
        int Month;
        int Day;

public:
        //Birthday(Birthday &b);//函数声明不需要加{}，还有声明的形式要跟下面定义的相一致
        Birthday(int y,int m,int d)
        {Year=y;
        Month=m;
        Day=d;}

  void Set(int y,int m,int d)
  {Year=y;
  Month=m;
  Day=d;}

  void Show()
  {
   cout<<Year<<" . "<<Month<<" . "<<Day;
  }
};

//Birthday::Birthday(Birthday &b)   
//{Year=b.Year;
//Month=b.Month;
//Day=b.Day;   
//}

//define class of Person
class Person
{
    int number;
    char sex;
    long int ID;
    int birthday;
public:
    Person(Person &p)
    {
      number=p.number;
      sex=p.sex;
      birthday=p.birthday;
      ID=p.ID;
    }

Person(int n,char m,long int id,long int bir)
{number=n;
sex=m;
ID=id;
birthday=bir;
}

void in_put()
{
cout<<"录入数据"<<endl;
cout<<"编号:";
cin>>number;
cout<<endl;
cout<<"性别:";
cin>>sex;
cout<<endl;
cout<<"生日:";
cin>>birthday;
cout<<endl;
cout<<"身份证号:";
cin>>ID;
cout<<endl;
}
void out_put()
{
cout<<"编号"<<number<<endl;
cout<<"性别"<<sex<<endl;
cout<<"生日"<<birthday<<endl;
cout<<"身份证号"<<ID<<endl<<endl;
}
};

//the main function
int  main()
{
    Person p(12,'f',123,56);                     
    Birthday birth(1984,10,30);
cout<<"the birthday is:  ";
birth.Show();
cout<<endl;

p.out_put();

return 0;
}