Classes Error How do i get this program to start

[faieq92]

	#include <iostream> 
	#include <string>
	#include <math.h> 
	#include <fstream>
	using namespace std;

class Details
{
public:
    Details(); 
    string FirstName;
    string LastName;
    int Age;
    string Email;
    int DoorNumber;
    string RoadName;
    string PostCode;
	
};

void SetInformation(Details &member)
{
    cout << "\nFirst Name: ";
    cin >> member.FirstName;

    cout << "\nLast Name: ";
    cin >> member.LastName;

    cout << "\nAge: ";
    cin >> member.Age;

    cout << "\nEmail: ";
    cin >> member.Email;

    cout << "\nDoor Number: ";
    cin >> member.DoorNumber;

    cout << "\nRoad Name: ";
    cin >> member.RoadName;

    cout << "\nPost Code: ";
    cin >> member.PostCode;
}

int main()
{	int i;
	Details	information[10];	
	cout << "\nWhich Slot would you like to store the informaton in ?(1-10)";
	cin >> i;
	i--;
	SetInformation(information[i]);
return 0;}

Can someone tell me what the problem in this bit of code could be..

1>attemp2.obj : error LNK2019: unresolved external symbol "public: __thiscall Details::Details(void)" (??0Details@@QAE@XZ) referenced in function _main
1>c:\users\faieq\documents\visual studio 2010\Projects\Attempt 2 CHallange 1\Debug\Attempt 2 CHallange 1.exe : fatal error LNK1120: 1 unresolved externals
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========


that's the error im getting

[vlad from moscow]

You did not define the default constructor. You only declared it in the class definition but forgot to define it.

[vlad from moscow]

If you have a question relative this thread then ask it here. Do not write a PM me. If you want to ask a question personally me you can do that at www.cpp.forum24.ru.

You can define the constructor inside the class definition or outside the class definition.

For example

class Details
{
public:
    Details() : Age( 0 ), DoorNumber( 0 ) {} 
    string FirstName;
    string LastName;
    int Age;
    string Email;
    int DoorNumber;
    string RoadName;
    string PostCode;
	
};

Or

class Details
{
public:
    Details(); 
    string FirstName;
    string LastName;
    int Age;
    string Email;
    int DoorNumber;
    string RoadName;
    string PostCode;
	
};

Details::Details() : Age( 0 ), DoorName( 0 ) {}

[faieq92]

I understand . That got it working. Also why do I need to do this?

SetInformation(Details &member) the pointer part?

[vlad from moscow]

It is not a pointer. It is reference to a class object. Changing it in the function results to changing the original object.