C++ Funtion/Include Problems.

Hi to all, I'm new here!

I'll give you a quick rundown of what I am trying to achieve.

A short while ago, I set about learning my first scrap of C++ coding, And have manage to successfully code a few simple programs, such a quiz's, add libs, etc. Now I am starting on my very own game, an RPG. I know it's a lot to dive in to right now, but I'm determined at heart.

Anyway, What I have a problem with is the funtionality of things such as

#include <includefile.h> etc.

What I am trying to do, is simple. I want a header file, that contains the following -

Mana = Intelligence X 2

And another file, Orc, which passes the variable Intelligence, to the header file, then the header file returns the variable, Mana.

here's the code for the orc (orc.cpp)

Code:

---

//
// RPG ORC
//
//
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <statcheck.h>
#include <string.h>
using namespace std;

//Prototype Declarations


int main(int nNarg, char* pszArgs[])
{
 
  int vitality = 10;
  int strength = 10;
  int intelligence = 2;
 
  int hitpoints = 1;

 
 
 

  cout << vitality << "\n";
  cout << strength << "\n";
  cout << intelligence << "\n";
 
  cout << hitpoints << "\n";
 
 
 
 
    //wait until user is ready before terminating the program
    // to all user to see the program results
    system("pause");
    return 0;
}

---

And here's the code for the header file (statcheck.h)

Code:

---

//
// Mana
//
//
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string.h>
using namespace std;

 
     
   

int main(int intelligence)
{
  int mana  = intelligence * 2;
    cout << mana << "\n";
 
   
    //wait until user is ready before terminating the program
    // to all user to see the program results
    system("pause");
    return 0;
}

---

I'm not sure what the heck i'm doing, so be kind :)

You only have 1 main function per program. I think what you're looking for is a function:

Code:

---

float GetMana(float Intelligence)
{
  return Intelligence * 2;
}

int main()
{
  ...

  ... = GetMana(3);
  ...
}

---

1. Headers should really only contain function prototypes, typedefs and things of that nature. Code should not come into play with headers unless you are dealing with templated code (which you are not).

2. A program cannot have two main functions. Your linker will complain when you attempt to build the program. The code that returns the "mana" should be a function called perhaps GetMana that accepts an int value denoting intelligence. All it needs to do is return twice the value that is input as the argument. The actual code for the function should be in a seperate source file, perhaps called StatCheck.Cpp or something.

I would alter your setup to something approaching the following:

Code:

---

//StatCheck.H
#ifndef STATCHECK_H
#define STATCHECK_H
int GetMana(int);  // Function prototype
#endif


//Orc.Cpp
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include "statcheck.h"
#include <string.h>
using namespace std;

int main(int nNarg, char* pszArgs[])
{
 
  int vitality = 10;
  int strength = 10;
  int intelligence = 2;
 
  int hitpoints = 1;

  cout << "Vitality: " << vitality << "\n";
  cout << "Strength: " << strength << "\n";
  cout << "Intelligence: " << intelligence << "\n";
  cout << "Hit Points: " << hitpoints << "\n";
  cout << "Mana: " << GetMana(intelligence) << "\n";
 
 
 
    //wait until user is ready before terminating the program
    // to all user to see the program results
    system("pause");
    return 0;
}


// StatCheck.Cpp
int GetMana(int intelligence)
{
    return intelligence * 2;
}

---

You now have a multi-sourcefile project that would require you to compile the two source files into object files and then link the two object files together to produce an executable program. How you do that depends on your available tools such as what compiler are you using? Is it an IDE or are you using a command-line compiler.

In the future such a program above would typically be done by creating a base "player" class and having such things as the GetMana function be a member function of the class. You would derive other classes such as Orc and maybe Dwarf and Human from this base "player" class.

Hmmm, not sure we are on the same page.

I want to have a file, call it monster X, which uses a file, Statcheck to determin the amount of mana it has.

I also want to be able to use Statcheck, for other monsters, e.g. Monster Y, Monster Z.

EDIT: Some one posted before I just did, this above post may be null and void!

ok... I'm having a difficult time with this, i'm sure if I get it once, It'll click though.

Could you define "Function Prototype"

1) No header between angled brackets, e.g.:

#include <string.h>

should ever have a .h extension. Only your headers, which are declared like this:

#include "myheader.h"

should have a .h extension. The line:

#include <string.h>

should be:

#include <cstring>

but since you aren't using any functions defined in <cstring>, you don't even need it.

2) An include statement just takes whatever is in the included file and inserts it at the spot of the include statement. So, while it may be good practice to just include function prototypes, class definitions, etc. in a .h file, you can put function definitions in there too.

Generally, you will just put your function prototypes and class declarations in an include file. If you don't include the function prototypes and class declarations before main(), and then you mention any of those function names or classes in main(), you will get an error. The compiler will shout out: "where the heck did this function name come from. I didn't see it defined anywhere!". It's similar if you do this:

n= 10;

The compiler will holler: "What is 'n'!". You have to declare n first:

int n;
n=10;

When you just include function prototypes and not the function definitions, you are telling the compiler: "Hey bud, here are some names you are likely to see down in main(). I haven't defined them for you here, but don't freak out, they are in some other .cpp files, which your buddy Mr. Linker will send to you as soon as he can. In the meantime, go ahead and compile the rest of the code." Because Mr. Compiler appreciates cordial treatment, he assents and admonishes you--"don't forget to put those function definitions in a .cpp file somewhere, or I'll make sure Mr. Linker stops you flat in your tracks." If you heed that warning and put your defintions in a .cpp file AND you include the header file in the .cpp file, Mr. Linker will sort everything out.

Quote:

---

Could you define "Function Prototype"

---

function:

Code:

---

int myFunc(int n)
{
      cout<<n<<endl;
}

---

function prototype:

int myFunc(int n);

Cheers.

Right, I'm getting the following error right now,

"9 C:\Dev-Cpp\CPP_Programs\Chap01\rpg\orc.cpp
declaration of C function `int "
When I try to compile it.

1)Post your code
2)Post the error
3)Put a big red: THE ERROR IS HERE on the line with the error.

I also added some details to the bottom of my previous post that you might want to read.

Code:

---

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include "StatCheck.H"
#include <cstring>
using namespace std;

int main(int nNarg, char* pszArgs[])
{ ERROR IS HERE
 
  int vitality = 10;
  int strength = 10;
  int intelligence = 2;
 
  int hitpoints = 1;

  cout << "Vitality: "  << vitality << "\n";
  cout << "Strength: " << strength << "\n";
  cout << "Intelligence: " << intelligence << "\n";
  cout << "Hit Points: " << hitpoints << "\n";
  cout << "Mana: " << GetMana(intelligence) << "\n";
 
 
 
    //wait until user is ready before terminating the program
    // to all user to see the program results
    system("pause");
    return 0;
}

---

Error at the bottom reads:

[Warning] In function `int main(int,:
declaration of C function `int
16 previous declaration `int this line is highlighted
[Warning] In function `int main(int)':
21 `GetMana' undeclared (first use
21 (Each undeclared identifier is

1) Get rid of "int nNarg, char* pszArgs[]"

Your basic main() function should look like this:

Code:

---

int main()
{

    return 0;
}

---

2) The compiler doesn't know what the GetMana() function is. Did you include any header file that has that function prototype or function definition in it? If the included file has the GetMana() prototype in it, did you create a .cpp file with the GetMana() function definition in it, AND did you include the header file in that .cpp file?

3) Stop everything you are doing with this program. Close the project. Start a new project. In your new project, create three files:

a) main.cpp
b) myfunction.h
c) myfunction.cpp


Your main.cpp file will have main() in it. Call a simple function in main(), like this:

Code:

---

int main()
{
        someFunc();
       
        return 0;
}

---

Include myfunction.h at the top of main.cpp:

Code:

---

#include "myfunction.h"

int main()
{
        someFunc();
       
        return 0;
}

---

In myfunction.h, put the function prototype:

//myfunction.h
#ifndef __MYFUNCTION_H__
#define __MYFUNCTION_H__

void someFunc();

#endif //__MYFUNCTION_H__

Those lines around the function prototype keep you from including the file twice somewhere, which will cause an error. Having those lines is standard practice for .h files.

In myfunction.cpp put the function definition along with the proper includes:

Code:

---

#include <iostream> //for cout, endl
#include "myfunction.h" //mandatory

using namespace std;

void someFunc()
{
        cout<<"hello world"<<endl;
}

---

If you can get that structure to work, you should have a better idea of how to do it with your current program.

I have done this. When I compile, it tells me


[Linker error] undefined reference to `someFunc()'

I'm still checking everything over right now.

I'm confused as to why you have a seperate header file for all these things. Why not use classes?

I don't know, you tell me. I am, to be quite honest, diving in head first to a dark hole. I don't know why not use classes. Would a class work for many differen't other files?

I don't know either.

I didn't even know you could make your own header files.

Quote:

---

I have done this. When I compile, it tells me

[Linker error] undefined reference to `someFunc()'

I'm still checking everything over right now.

---

What compiler are you using? You have to make sure all the files are part of your project. In addition the file extensions must be correct: .h for the header file, and .cpp for the file with the definitions.

Using multiple files is not some alternative to classes. It has to do with program organization. If you had a class, you would organize your program the same way:

main.cpp:

Code:

---

#include "header.h"

int main()
{
        One myone;
        myone.display();

        Two mytwo(3.2);
        mytwo.show();
       
        return 0;
}

---

header.h:

Code:

---

#ifndef __HEADER_H__
#define __HEADER_H__

////CLASS ONE//////
class One
{
private:
        int num;

public:
        One(int n);
        One();
        void display();
};

//////CLASS TWO//////
class Two
{
private:
        double time;

public:
        Two(double t);
        Two();
        void show();
};

#endif //__HEADER_H__

---

definitions.cpp:

Code:

---

#include <iostream>
#include "header.h"

using namespace std;

////DEFINITIONS/////

One::One(int n)
{
        num = n;
}

One::One()
{
        num = 0;
}

void One::display()
{
        cout<<num<<endl;
}

Two::Two(double t)
{
        time = t;
}

Two::Two()
{
        time = 1.0;
}

void Two::show()
{
        cout<<time<<endl;
}

---

You don't have to organize your code that way. Instead, you can just include everything in one file, which I suggest you do if you are having too much trouble with the multiple file concept. For instance, the same program above contained in a single file:

Code:

---

#include <iostream>
using namespace std;

////CLASS ONE//////
class One
{
private:
        int num;

public:
        One(int n);
        One();
        void display();
};

//////CLASS TWO//////
class Two
{
private:
        double time;

public:
        Two(double t);
        Two();
        void show();
};

//////MAIN//////////
int main()
{
        One myone;
        myone.display();

        Two mytwo(3.2);
        mytwo.show();
       
        return 0;
}

////DEFINITIONS/////

One::One(int n)
{
        num = n;
}

One::One()
{
        num = 0;
}

void One::display()
{
        cout<<num<<endl;
}

Two::Two(double t)
{
        time = t;
}

Two::Two()
{
        time = 1.0;
}

void Two::show()
{
        cout<<time<<endl;
}

---

Quote:

---

Originally Posted by 7stud

You don't have to organize your code that way. Instead, you can just include everything in one file, which I suggest you do if you are having too much trouble with the multiple file concept. For instance, the same program above contained in a single file:

---

This is exactly what I am trying to avoid. The point in this particular project is teaching me to use multiple files. And From what I can see, I know roughly how it works.

I am useing

Bloodshed Dev-C++4.9.8.0.

The name of all files are

main.cpp, Which contains:

Code:

---

#include <iostream>
#include "myfunction.h"

using namespace std;

int main()
{
        someFunc();
       
        return 0;
}

---

myfunction.cpp, which contains

Code:

---


#include <iostream>
#include "myfunction.h"

using namespace std;

void someFunc()
{
        cout<<"hello world"<<endl;
}

---

myfunction.h, which contains

Code:

---


//myfunction.h
#ifndef __MYFUNCTION_H__
#define __MYFUNCTION_H__

void someFunc();

#endif //__MYFUNCTION

---

I don't know what's wrong, other than that linker problem.

Sorry, I don't know anything about your compiler. If you are getting a linker error, that means Bloodshed can't find one of the files. I would read up on how to add files to a project in Bloodshed. For instance, I can have a file open in my compiler(MS VC++6) along with the other files, and it doesn't mean it's part of the project. I have to specifically insert any new file I create into the project.

If you can't figure out how to add files to a project, post a new thread titled something like:

"How the !#$@!#$ can I add files to a project with Bloodshed"

There should be many people on this forum that can help you with that.

thanks for the advice.

This happens to me when I use DevC++ if I forget to save the source file I use as a header file as a .h file type. Here's what I'd try:

Code:

---

1) Open DevC++.
2) Click on File->New->Project.
3) Choose console project of type c++ and name the  project multifilePractice.
4) Compile the barebones project that comes up and save the file as multifilePractice of File Type .cpp.
5) Click on File->New->Source File
6) Add the line: void someFunc(); to the blank file
7) Compile the project. 
8) Save the Untitled file using the name myFunctions of File Type .h 
9) Click on File->New->Source File
10) Add the lines:
 
#include<iostream>
#include "myFunctions.h"
 
using namespace std;
 
void someFunc()
{
  cout << "hello world" << endl;
}
to the blank file.
 
11) Compile the project.
12) Save the file using the name myFunctions and  using File Type .cpp
13) Add the line #include myFunctions.h" to mulifilePractice.cpp.
14) In main() add the line: someFunc(); before the line: system(PAUSE);
15) Compile and run the project
16) Add the inclusion gaurds to myFunctions.h as recommended by 7stud

---

eGads. I am now so very happy. I could wet the bed! WOOHOOOOO!

Thank you all so much!

Seems that my happines was meant to be shot down.

Code:

---

//StatCheck.H
#ifndef STATCHECK_H
#define STATCHECK_H
int GetMana(int);
int GetHP(int);  // Function prototype
#endif

---

Is that kind of code there, ok? Can I declare multiple things such as "GetMana(int)" and "GetHP(int)" as I did there? I can't get it working ;)

Right. Scrap the previous post. I'm still having linker problems, even though I have put them all in the same project.

Here's the differen't files I have.

Main.cpp

Code:

---

#include <iostream>
#include <stdlib.h>
#include <iostream>
#include "monster.h"

using namespace std;

int main()
{
 
 int OwnVitality;
 int OwnStrength;
 int OwnInteligence;
 int HitPoints;
 string name;
 
 cout << "Greetings. I am Simpleton. Welcome to this land. \n";
 cout << "And, young traveller, you might be? \n";
 cin >> name;
 cout << "Ah, " << name << "! Yes, That's right, now I remember. \n";
 cout << "Well, There's no time to waste, let's throw you in to your first fight \n";
 
 
 
  int Orc();


 
  system("PAUSE");       
  return 0;
}

---

statcheck.cpp

Code:

---

// StatCheck.Cpp
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include "monster.h"
#include "statcheck.h"

using namespace std;


int GetStat(intelligence)

{
 
          return intelligence * 2;
       
}

---

statcheck.h

Code:

---

//StatCheck.H
#ifndef _STATCHECK_H
#define _STATCHECK_H
int GetStat(int); // Function prototype
#endif

---

monster.cpp This is the file with the error in, the error reads: "27 C:\Dev-Cpp\CPP_Programs\rpg\monster.cpp
`GetStat' undeclared (first use this function)"

Code:

---

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include "statcheck.h"
using namespace std;

int Orc()
{
 
  int vitality = 13;
  int strength = 10;
  int intelligence = 2;
  string name = "Orc";
  int hitpoints;
  string eval;

  cout << "You see an " << name << "\n";
  //cout << "Vitality: "  << vitality << "\n";
  //cout << "Strength: " << strength << "\n";
  //cout << "Intelligence: " << intelligence << "\n";
  cout << "Do you wish to evaluate the " << name << "? \n";
  cout << "Y or N? \n";
  cin >> eval; 
  if (eval == "Y")
    {
        cout << "Stats: " cout << "Stats: " << GetStat(intelligence) << "\n"; THE ERROR IS HERE
     
    }

 
    //wait until user is ready before terminating the program
    // to all user to see the program results
    //system("pause");
    //return 0;
}

---

monster.h

Code:

---

//Monster.H

#ifndef _MONSTER_H
#define _MONSTER_H
int Orc();  // Function prototype
#end

---

Oddly enough, "int orc()" works fine.

Quote:

---

int GetStat(intelligence)

---

Shouldnt this be:
int GetStat(int intelligence)
?

Also, in monster.h, you should use #endif instead of #end

Post your compile log.

In monster.h, it IS #endif, I just copied it wrong.

Should it be (int intelligence) if intelligence is already declared? (edit - It should be "mana" there, intelligence is already defined as 2, and mana is derived from intelligence)

Compile log - Is that the part at the bottom? with the errors in? Or some kind of externally created file?

EDIT: I found the compile log

Code:

---

Compiler: Default compiler
Building Makefile: "C:\Dev-Cpp\CPP_Programs\rpg\Makefile.win"
Executing  make...
make.exe -f "C:\Dev-Cpp\CPP_Programs\rpg\Makefile.win" all
g++.exe -c monster.cpp -o monster.o -I"C:/Dev-Cpp/include/c++"  -I"C:/Dev-Cpp/include/c++/mingw32"  -I"C:/Dev-Cpp/include/c++/backward"  -I"C:/Dev-Cpp/include" 

monster.cpp: In function `int Orc()':
monster.cpp:17: `GetStat' undeclared (first use this function)
monster.cpp:17: (Each undeclared identifier is reported only once for each
  function it appears in.)

make.exe: *** [monster.o] Error 1

Execution terminated

---

You need to get a C++ book, and look at the required elements for a function definition:

1) return type
2) function name
3) if any parameters, then a list of parameters plus their types
4) function body

So, in your function definition here:

Code:

---

int GetStat(intelligence)

{
 
          return intelligence * 2;
       
}

---

you are missing one of the required elements.

Using Functions:

Here is a simple example of a function:

Code:

---

void display(int n)
{
        cout<<n<<endl;
}

---

All functions require a return type. In the display() function above, the return type is 'void', which stands for 'nada', 'nothing', 'zip'. That means, the function doesn't return anything. Functions also can have things called 'parameters'. The parameter in the function above is 'int n'. That means the function is expecting any integer to be sent to it. The integer value that is sent to the function will be stored in the variable 'n'.

Here is what the function looks like as part of a program:

Code:

---

#include <iostream> //contains cout

using namespace std;
//makes it so you don't have to write 'std::cout'
//instead you can just write 'cout'


//function:
void display(int n)
{
        cout<<n<<endl;
}


int main()
{
        int num = 10;
        display(num);

        return 0;
}

---

In main(), the function is called by this line:

display(num);

That instructs the program to send the value contained in the variable 'num' to the function named display(), and then execute the code in the function. Since num is equal to 10, 10 is sent to the display() function. The value 10 is then stored in the variable 'n', which is the function parameter. Then, the code in the function is executed. After the last line in the function is executed, execution returns to the place in main() where the function was called, and then the statements thereafter in main() are executed.

Here is another example of a function:

Code:

---

double multiplyBy3(int x)
{
        double temp = x * 3.0;
        return temp;
}

---

This time the return type is double(a double is a number with a decimal point like 2.5). The return type has to be specified as 'double' because the function returns a double value in this line:

return temp;

The multiplyBy3() function also has an int parameter, so it must be sent an int.

Adding the multiplyBy3() function to the previous program looks like this:

Code:

---

#include <iostream> //contains cout

using namespace std;
//makes it so you don't have to write 'std::cout'
//instead you can just write 'cout'

double multiplyBy3(int x)
{
        double temp = x * 3.0;
        return temp;
}

void display(int n)
{
        cout<<n<<endl;
}


int main()
{
        int num = 10;
        display(num);

        int number = 5;
        double result = multiplyBy3(number);
       
        cout<<result<<endl;

        return 0;
}

---

The function multiplyBy3() is called in main() by this line:

double result = multiplyBy3(number);

The function is sent the int value stored in number. Since number is equal to 5, 5 is sent to the multiplyBy3 function, and then 5 is stored in the variable 'x', which is the function parameter. Then, the code in the function is executed. When the return statment is executed:

return temp;

the function gets the value in temp, and sends it back to main(). Since temp equals 15.0, 15.0 is sent back to main(). When a function returns a value, the function call is replaced by the return value. So, this line in main():

double result = multiplyBy3(number);

becomes:

double result = 15.0;

Then, the line:

cout<<result<<endl;

displays the return value. Note that you cannot do this to display 'result':

display(result);

The display() function requires an int to be sent to it, not a double, and result is type double. Therefore, you would get an error if you tried that: the types have to match.

I don't understand what that has to do with why my compiler won't recognise the function that I have?

Quote:

---

Is that kind of code there, ok? Can I declare multiple things such as "GetMana(int)" and "GetHP(int)" as I did there?

---

Yes. However, to make it less confusing for you, I would make sure my function declaration/prototype is exactly the same as the first line of your function definition--copy and paste it to be absolutely sure.

Quote:

---

This is the file with the error in, the error reads: "27 C:\Dev-Cpp\CPP_Programs\rpg\monster.cpp
`GetStat' undeclared (first use this function)"

---

There shouldn't be an error there, IF you named your files correctly. However, looking at your code, I consider that suspect:

Quote:

---

monster.cpp :

Code:

---

#include "statcheck.h"

---

---

Quote:

---

statcheck.h

Code:

---

//StatCheck.H
#ifndef _STATCHECK_H
#define _STATCHECK_H
int GetStat(int); // Function prototype
#endif

---

---

It doesn't matter what the file name is, but the exact filename has to be in the include:

Code:

---

#include "statcheck.h"

---

Quote:

---

I don't understand what that has to do with why my compiler won't recognise the function that I have?

---

It doesn't, but once you get the file thing straightened out, that will be your next problem.

It is exactly the same.

1) Is the include file part of the project?

2) I'm pretty sure it's mandatory that you have to include monster.h in monster.cpp--that was one of the first things we discussed in this thread. I already discussed why you need to include the .h file in main(): it's just like declaring a variable before using it. However, the linker also needs the function declaration(.h file) and the function definition(.cpp file) together in one file(the .cpp file including the .h file) to sort things out. It's the one part of the whole multiple file scenario that doesn't really make sense, i.e. you have to include the .h file for the function in main(), and you have to again include the .h file for the function in the .cpp file for the function.

See if that works.

As a side note, this including stuff gets very complicated as the number of files increases because functions in one file might call functions in other files that may call functions in yet other files. That is why you put those inclusions guards around .h files. If things get too confusing as to what .h files need to be included in a certain.cpp file--just add every .h file in your program to the .cpp file, and the inclusion guards will make sure you don't add the .h file more than once.

Yeah, All the above works. monster.h already works. It's GetStat in statcheck.h and statcheck.cpp that doesn't work.

Monster.cpp is calling in GetStat() from statcheck.cpp/h

That's where it doesn't work. Everything else works fine. If I remove GetStat from the program, it compiles and runs great.

EDIT: Also, On the left, I have it added to the project. It's all there. But in the compile log, I see no signs of statcheck.h or statcheck.cpp

Helllloooo? Did you do this:

Quote:

---

I'm pretty sure it's mandatory that you have to include monster.h in monster.cpp

---

The monster.cpp file you posted does not do that, and I tested it and it got rid of your error.

This stuff is frustrating, eh? :)

If we could see your files, we could spot the error in 10 seconds, but it's so darn laborious to post all the files and their names.

I suggest you get rid of monster.cpp and monster.h and try to get statcheck.h and statcheck.cpp to work with main().

I want to reiterate the #1 Rule of debugging: you fix any obvious errors FIRST. The compiler is even directing you to GetStat(), and as I posted before:

Quote:

---

So, in your function definition here:

Code:

---

int GetStat(intelligence)

{
 
          return intelligence * 2;
       
}

---

you are missing one of the required elements.

---

I'm betting you never fixed that even though the compiler told you there is something the matter with that function.

In addition, what is this:

Code:

---

main()
{
    ...
    ...

    int Orc();
}

---

I suggest you read that post about Using Functions several times. If you don't know the basics of how to call, define, and declare functions, how can you expect to get that all straight in multiple files? :(

This compiled 2nd try:

Code:

---

//main.cpp

#include <iostream>
#include "monster.h"

using namespace std;


int main()
{
       
        Orc();

        return 0;
}

---

Code:

---

//monster.h

#ifndef __MONSTER_H__
#define __MONSTER_H__

int Orc();

#endif //__MONSTER_H__

---

Code:

---

//monster.cpp

#include "statcheck.h"

int Orc()
{
        int intelligence = 100;

        GetStat(intelligence);

        return 10;
}

---

Code:

---

//statcheck.h


#ifndef __STATCHECK_H__
#define __STATCHECK_H__

int GetStat(int);

#endif //__STATCHECK_H__

---

Code:

---

//statcheck.cpp

#include "statcheck.h"

int GetStat(int intel)
{
        return 100;
}

---

Lol, I've been reading reading and re-reading this entire thread.

I'm pretty sure I'm getting there. Let me try "explaining" it.

In a .h file, you are basically letting the other files know, that this name e.g. functionX() will appear below, and it's nothing to worry about, because the defintion is in functionX.cpp

yeah?

So I define in functionX.cpp

Code:

---

#include "functionX"
using namespace ctd;
int functionX()

{

random code here

}

---

and then in the function.h file, i'd have

Code:

---

//functionx.h
#ifndef _FUNCTIONX_H
#define _FUNCTIONX_H
int functionX();  // Function prototype
#endif

---

then in main.cpp

I would have

Code:

---

int main
{

functionX()

return 0;

}

---

Is that right?

I'll attatch my files, so you can look at them.

edit: By the way, I'm not expecting you to change them, but If you do, make comments in the code and let me know what you changed, or what I should change it too, or smack me because I did something stupid ;) oh and yes, this is frustrating. three days on one little problem.

#include "functionX"

should be:

#include "functionX.h"

Quote:

---

then in main.cpp

I would have

Code:

---

int main
{

functionX()

return 0;

}

---

Is that right?

---

Nope. :) What happened to this line of reasoning:

Quote:

---

Let me try "explaining" it.

In a .h file, you are basically letting the other files know, that this name e.g. functionX() will appear below, and it's nothing to worry about, because the definition is in functionX.cpp

---

Let's say your are a compiler. You are merrily reading down main() and all of a sudden your reverie is interrupted by:

functionX();

What the heck you say??!! Where did this intruder come from??!! I was never warned about having visitors today?!! I quit!

Just like declaring a variable, you have to declare your functions before calling them, and functionX() was never declared in main(). Rememberer an 'include' just inserts the contents of the file at the include statement. That's why you need to include functionX.h in main(): it declares the function before you call it, which alerts the compiler that the function name it will see mentioned down in main() is defined in another file, and not to worry about the missing function definition.

There are three types of function statements:

1) a declaration/prototype: int functionX(int num);

2) a function call: functionX(20);

3) a function definition:

Code:

---

int functionX(int num)
{
    return num * 100;
}

---

The only place that the line of reasoning that says, "you must declare a function before calling it", breaks down is: why do you have to include functionX.h in functionX.cpp? After all functionX.cpp just defines the function--it doesn't call it. I'm not really sure about that, but the #1 rule is: functionX.h has to be included in functionX.cpp. Then, after you include functionX.h in functionX.cpp, you worry about what other header files need to be in functionX.cpp. If there are other function names that are defined in other .cpp files that are mentioned in functionX.cpp, then you have to include their header files too--that gets back to the rule that says, "you have to declare a function before calling it".

Stupidly, I knew that. An honest mistake.

Right now, In statcheck.cpp, I've changed the function getstat() definition to

Code:

---

// statcheck.Cpp
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include "monster.h"
#include "statcheck.h"

using namespace std;


int GetStat(int intelligence)

{
 
          return intelligence * 2;
       
}

---

Is that what I was missing?

That was the only problem I could see with StatCheck. :)

You still have that int Orc() problem in main(). :(

I've changed that to

Code:

---

Orc();

---

That correct?

Man I love coding. ;) I made the biggest thread on the page.

lol. Is it FINALLY working???

Nope :(

Still not recognising GetStat()

I'm guessing a problem with Dev-C++

You can always test that by taking the files I posted and copying them into a new project, and seeing if it compiles. Create the project, then create each file, and copy and paste from above. It shouldn't take long.

Roger wilco. Will report back with results.

About the files you posted: I don't download files from the internet from anonymous sources, and the one time I made an exception to that rule was when someone posted an answer to a Visual C++ question I had that I really wanted to see, and my compiler was completely messed up for weeks after that....so I won't be able to see them unless you post them in code tags.

That works. (no result as such, just runs and closes straight away)

What I'm going to do, is get all my code, then remake the project. Just like I did with yours. Maybe Something went odd along the way.

Start off by creating a main.cpp, statcheck.h, and statcheck.cpp. Get those to compile before adding monster.h and monster.cpp.

I did. That worked.

Then I added monster.cpp and monster.h.

There was an error. (i typed #end instead of #endif)

So I fixed that.

AND IT F@£"!G WORKS!

Thank you so much for your help. I think it must be something to do with how I added to the project, Something didn't compute (maybe an error since I'm using the last "stable" release, methinks) So from now on, people if you have problems including files, a better way to do it than the "add to project" feature, is to

Right click on the project in the left section
Click "new file"
Copy paste your code in
then "rename file"

Done.

Thank you so much 7stud. Maybe one day I will be able to help people code on here too :D

Alriiight!

You can learn a lot by explaining things to other people. In addition, as you get more experienced you tend to lose touch with how beginners think, so a beginner can often explain things better to another beginner. No matter how much a person knows about programming, there is usually someone somewhere who can program circles around them. So, jump in any time. :)

Lol, I've already run in to my next set of problems, but this time I have some limited Idea about them, so it shouldn't be a problem.

By the way, you might want to download a newer version of Dev-C++.

The current version is 4.9.9.2, and the next might just be the 5.0 final, if everything goes right.