Error when using namespaces - class not declared

Question

I'm new to C++ and using namespaces and I can't see what I'm doing wrong here. When I compile the code below, I get the error:

error: 'Menu' has not been declared

Here is my header file Menu.hpp

#ifndef MENU_H //"Header guard"
#define MENU_H

namespace View
{
class Menu
    {
    void startMenu();
    };
}
#endif

and my Menu.cpp:

#include "stdio.h"
using namespace std;

namespace View
{
 void Menu::startMenu()
    {
    cout << "This is a menu";
    }
}

`#include "Menu.hpp"` in your `Menu.cpp`. – Mark Garcia Aug 25 '13 at 06:04 — Mark Garcia, Aug 25 '13 at 06:04

score 4 · Answer 1 · edited May 23 '17 at 12:08

4

You missed including the header file which defines the class.

Menu.cpp:

#include "Menu.hpp"

Each translation unit is compiled separately by the compiler and if you do not include the header file in Menu.cpp, there is no way for the compiler to know what Menu is.

edited May 23 '17 at 12:08

Community

1
1

answered Aug 25 '13 at 06:06

Alok Save

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Thanks, I didn't realise each class had to include it's own header. – Dawson Aug 25 '13 at 06:23

score 3 · Accepted Answer · answered Aug 25 '13 at 06:05

3

You will have to include header Menu.hpp in your cpp file Menu.cpp like

#include "Menu.hpp"

answered Aug 25 '13 at 06:05

Saksham

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Error when using namespaces - class not declared

2 Answers2