error LNK2019: unresolved external symbol (simple code)

Question

this is a pretty simple code that just is coming up with an error even though I have it written the same way other people doing the same code have it

1>assigntment5.obj : error LNK2019: unresolved external symbol "class std::basic_string,class std::allocator > __cdecl promptForString(class std::basic_string,class std::allocator >)" (?promptForString@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@@Z) referenced in function _main 1>c:\users\aweb\documents\visual studio 2010\Projects\Assignment5\Debug\Assignment5.exe : fatal error LNK1120: 1 unresolved externals

the .cpp file

#include <iostream>
#include <string>
#include "anw65_Library.h"

using namespace std;

string promptForString(string prompt);

int main()
{
string name = promptForString("What is the filename?: ");

system("pause");
return 0;
}

the .h file

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

static string promptFromString(string prompt)
{
string filename;
cout << prompt;
cin >> filename;
return filename;
}

Ed S. Ed S. · Accepted Answer · 2013-02-22T02:21:01

You never define prompt**For**String, you defined prompt**From**String. Spelling matters. Also:

Why are you defining functions in your .h file? Just declare them there and define them in the .cpp file (unless they're templates).
Don't put using namespace <whatever> in a header file. You're just mucking up the global namespace of whatever includes your header.
You don't need to mark that function as static.

error LNK2019: unresolved external symbol (simple code)

3 Answers