Question

Good afternoon. I am starting with Visual c++ and I have a compilation problem I dont understand.

The Errors I get are the following :

error LNK1120 external links unresolved

error LNK2019

I paste the code:

C++TestingConsole.CPP

#include "stdafx.h"
#include "StringUtils.h"
#include <iostream>

int _tmain(int argc, _TCHAR* argv[])
{
using namespace std;
string res = StringUtils::GetProperSalute("Carlos").c_str();
cout << res;
return 0;
}

StringUtils.cpp

#include "StdAfx.h"
#include <stdio.h>
#include <ostream>
#include "StringUtils.h"
#include <string>
#include <sstream>
using namespace std;


static string GetProperSalute(string name)
{
return "Hello" + name;
}

Header: StringUtils.h

#pragma once
#include <string>
using namespace std;



class StringUtils
{

public:

static string GetProperSalute(string name);

};

Answer 1

You only need to declare the method static in the class definition and qualify it with the class name when you define it:

static string GetProperSalute(string name)
{
return "Hello" + name;
}

should be

string StringUtils::GetProperSalute(string name)
{
return "Hello" + name;
}

Other notes:

• remove using namespace std;. Prefer full qualifications (e.g. std::string)
• your class StringUtils seems like it would be better suited as a namespace (this will imply more changes to the code)
• string res = StringUtils::GetProperSalute("Carlos").c_str(); is useless, you can just do: string res = StringUtils::GetProperSalute("Carlos");
• pass strings by const reference instead of by value: std::string GetProperSalute(std::string const& name)