passing string type in multi-file compilation

[hybzik]

After using c-strings / character arrays for a year now I'm being encouraged to use the string type instead. After getting some errors in a multi-file project where i passed strings, I checked textbooks, websites... still not working.

So I wrote a simple test program. But even that isn't working. I'm pulling my hair out trying to figure out what I'm doing wrong, because I know it's probably something really simple to fix.

Why can't I get it to work?

here's the code:

MAIN.CPP

#include <iostream>
#include "foo.h"
using namespace std;

int main()
{
	string foo;
	cin >> foo;

	cout << foobar(foo) << endl;

return 0;
}

FOO.CPP

#include <iostream>
//#include "foo.h"

int foobar(string bar)
{
	cout << bar;
	return 1;
}

FOO.H

#include <string>

int foobar(string);

I can paste the errors (from g++ and CC) if that helps.

[helios]

using namespace only applies to the source where it is used. Although my personal recommendation is that you pretend it doesn't exist and just write the whole type (std::string).

[Danielsson]

When using string type you have always to use either using namespace std; or explicit notation std::string because string type is a member of std namespace.

You have used using namespace std; only in your main.cpp file so this would compile whilst foo.cpp wouldn't.

In header files (foo.h) is generally better to use the explicit notation std::string because in some cases you don't want to use using namespace std; in all files which #include your header file.

[hybzik]

checked back for replies and even before I read any of them I noticed the missing line. o_o

I am literally LOLing right now.
sorry for using up your time guys.