Thread: Creating Header Files

> #ifndef _FUNCTION_H
Pick another name. Everything which begins with _ is reserved, so you should avoid using it yourself.

This helped Everything is working as intended now, thanks for the help!

Originally Posted by laserlight

Interesting. I cannot duplicate that error in Dev-C++.

Really? Are we using the same version?

Just for clearance:

This is the faulty version:

Code:

#ifndef _FUNCTION_H
#define _FUNCTION_H

#include <windows.h>

inline void printout(char sentence[], int length, int interval)
{
     int x;
     for (x=0; x<length; x++)
     {
         cout<< sentence[x];
         Sleep(interval);
     }
}

#endif

And the working one:

Code:

#ifndef FUNCTION_H
#define FUNCTION_H

#include <windows.h>
#include <iostream>
using namespace std;

inline void printout(char sentence[], int length, int interval)
{
     int x;
     for (x=0; x<length; x++)
     {
         cout<< sentence[x];
         Sleep(interval);
     }
}

#endif

Originally Posted by laserlight

Ah, now I get it. It does look like you have given us a working example where failure to comply with the standard gives you a headache.

Indeed, as i said, very frustrating...

In general, placing C++ code inside header files ( or .h files ) is bad practice. Header files should only really contain function prototypes and class delcarations. All class and function bodys should be stored in the attached C++ source file (.cpp ) This increases program matienence and makes it clearer your intentions

Originally Posted by swgh

In general, placing C++ code inside header files ( or .h files ) is bad practice. Header files should only really contain function prototypes and class delcarations. All class and function bodys should be stored in the attached C++ source file (.cpp ) This increases program matienence and makes it clearer your intentions

How do i "attach" a .cpp file to a header file?

>> Interesting. I cannot duplicate that error in Dev-C++.

Seeing how Dev-C++ supposedly isn't a compiler I don't see how any one could.

Originally Posted by laserlight

You just implement the functions whose prototypes are in the header file, and then compile the source files and link them. If you are using some IDE with some kind of project mechanism, this compilation and linking will all be done for you.

Ah, i get it now. Thanks once again.

This is really giving me a headache!

I now separated the function prototype and the body of the function into a header and a .cpp file.

First time around, it worked beautifully, but now im getting all kinds of compiler warnings.

Here are the files:

Main

Code:

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

using namespace std;

int main()
{
    char sentence1[] = "Still ain't working!";
    int length = strlen(sentence1);
    printout(sentence1, length, 100);
    std::cin.ignore();
}

Header

Code:

#ifndef PRINTOUT_H
#define PRINTOUT_H

inline void printout(char sentence[], int length, int interval)

#endif

"attached" source file

Code:

#include <windows.h>
#include <iostream>

inline void printout(char sentence[], int length, int interval)
{
       int i;
       for (i = 0, i < length, i++)
       std::cout<< sentence[i];
       Sleep(interval);
       }
}

expected init-declarator before "using"
expected `,' or `;' before "using"
`printout' undeclared (first use this function)

I just wrote the source files with Dev-C++ in the same project as main and the headers, and as i said, it worked perfectly, but now it just won't compile. I even tried closing Dev-C++ and rewriting the entire application.

Btw: If i want to inline a function, do i have to inline it in the prototype or in the actual declaration? Or both perhaps?