我刚学C++,今天编写了一个程序，可以compile,但是无法build,不知怎么回事儿，望各位达人指正。
程序如下：
#include <stdio.h>
#include <iostream.h>
#include <iomanip.h>
class Customer
{
public:
char Id[5];
char Firstname[12];
char Lastname[16];
char Address[30];
char Suburb[16];
char Postcode[4];
char BirthDate[10];
public:
Customer();
void ReadCustomer();
void ShowCustomer();
};
void Customer::ReadCustomer()
{
cout<<"Enter Id number: ";
cin>>Id;
cout<<"Enter firstname: ";
cin>>Firstname;
cout<<"Enter lastname: ";
cin>>Lastname;
cout<<"Enter address: ";
cin>>Address;
cout<<"Enter address: ";
gets(Address);
cout<<"Enter suburb: ";
cin>>Suburb;
cout<<"Enter postcode: ";
cin>>Postcode;
cout<<"Enter birth date:";
cin>>BirthDate;
}
void Customer::ShowCustomer()
{
cout<<"Id number: "<<Id<<endl;
cout<<"Name: "<<Firstname<<" "<<Lastname<<endl;
cout<<"Address: "<<Address<<endl;
cout<<"BirthDate: "<<BirthDate<<endl;
}
void main()
{
Customer C;
C.ReadCustomer();
C.ShowCustomer();
}


错误如下：
ex11bq1.obj : error LNK2001: unresolved external symbol "public: __thiscall Customer::Customer(void)" (??0Customer@@QAE@XZ)
Debug/ex11bq1.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

ex11bq1.exe - 2 error(s), 0 warning(s)

没有实现Customer(); Customer的构造函数，声明了，就要实现。

OK,谢谢美女了。
但是！有后续问题。
怎么说呢，去掉构造函数后，程序的确可以运行了，但是和想象中的不一样。
当按照程序提示输入到Lastname的时候，程序突然没有提示了！
敲击回车键，应该正常显示的“Enter address:”和“Enter suburb”一起跳了出来，当完成所有输入的时候，效果显示如下：

Enter Id: 12345
Enter firstname:Zealot
Enter lastname:One

Enter Address: Enter suburb:Preston
Enter postcode:1411
Enter birthdate:1/1/1985
Id: E12345Zealot
Firstname:Zealot
Lastname:One
Address: Preston
Birthdate:1/1/1985
Press anykey to continue

那位大虾帮我解决一下，感激不尽！

我试了一下。没有问题，
Enter Id number: 001
Enter firstname: 002
Enter lastname: 33
Enter address: 44
Enter address: 44
Enter suburb: 395
Enter postcode: 392
Enter birth date:343535
Id number: 001
Name: 002 33
Address: 44
BirthDate: 343535

你使用VC++吗？

哦，程序有点问题，这是我重新写的：
#include <stdio.h>
#include <iostream.h>
#include <iomanip.h>
class Customer
{
public:
char Id[5];
char Firstname[12];
char Lastname[16];
char Address[30];
char Suburb[16];
char Postcode[4];
char BirthDate[10];
public:
void ReadCustomer();
void ShowCustomer();
};
void Customer::ReadCustomer()
{
cout<<"Enter Id number: E";
cin>>Id;
cout<<"Enter firstname: ";
cin>>Firstname;
cout<<"Enter lastname: ";
cin>>Lastname;
cout<<"Enter address: ";
gets(Address);
cout<<"Enter suburb: ";
cin>>Suburb;
cout<<"Enter postcode: ";
cin>>Postcode;
cout<<"Enter birth date:";
cin>>BirthDate;
}
void Customer::ShowCustomer()
{
cout<<"Id number: E"<<Id<<endl;
cout<<"Name: "<<Firstname<<" "<<Lastname<<endl;
cout<<"Address: "<<Address<<" "<<Suburb<<endl;
cout<<"BirthDate: "<<BirthDate<<endl;
}
void main()
{
Customer C;
C.ReadCustomer();
C.ShowCustomer();
}

我用Borland C++。没有问题

VC下面我试了，如果cout<<"Enter address: ";
gets(Address);
这里用cin>>Address，就没错。

BC在哪里下载？

但其实问题是：在英文输入中，往往地址是带有空格的字符串，如果用cin>>的话，程序就会运行不正常，斑竹有办法解决吗？