Thread: Separating class implementation

I was reading Deitels' book, and in one of the chapters the reader is supposed to learn how to implement classes by separating the interface in a header file, and the code itself on a source code file.

They use an example where you define a class "GradeBook" that will create a GradeBook for a certain class, and has member functions to set the class name, read the class name and display a "welcome" message.

The problem is I can't even compile the function code... It always returns an error. First it was returning some errors about the class implementation, and now it's returning a linker error...

Anyone knows what's wrong with the code?

gradebook.cpp:

Code:

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

using std::cout;
using std::string;

GradeBook::GradeBook(string name){
                     setCourseName(name);
                     }
                     
void GradeBook::setCourseName(string name){
     courseName = name;
     }
     
string GradeBook::getCourseName(){
       return courseName;
       }
       
void GradeBook::displayMessage(){ 
     cout << "Welcome to GradeBook for: " << getCourseName();
     }

gradebook.h:

Code:

#include <string>

using std::string;

class GradeBook
{
      public:
             GradeBook(string);
             string getCourseName();
             void setCourseName(string);
             void displayMessage();
      
      private:
              string courseName;
};

I'm not including the main code as the problem is only the class.

Any help appreciated.

Originally Posted by Litz

The problem is I can't even compile the function code... It always returns an error. First it was returning some errors about the class implementation, and now it's returning a linker error...

Anyone knows what's wrong with the code?

On a quick look, the code you've supplied looks alright (albeit not doing things in a particularly good manner, but that's subjective).

Your words here also imply you're trying various things (eg hacking your code, tweaking compiler settings) and it's quite possible the code you've shown isn't actually related to the problems you're seeing. If you're getting compiler errors, there is no point in trying to link.

In any event, it would be helpful if you posted information about your development environment (which compiler, compiler settings, IDE options set, etc). And, most importantly, what error messages you're seeing.

It would also help if you provided the "main code", as there are things you could be doing in there that would cause compiler errors. For example, multiple inclusions of "gradebook.h" and "gradebook.cpp" within your main code would upset the compiler.

FYI,
Don't remove parameter names from prototypes.
And Indentation.