How do I add a header file to my project?

[357mag 3]

I'm looking around the IDE for something that will allow me to add a header file to my project. Do I right-click on the project and just select Add Unit? I also need to add a .cpp file too.

Edited December 30, 2024 by 357mag

[357mag 3]

Oh I believe I found it. Anyway I made my first project that uses a header file to hold the function prototype, and a .cpp file that holds the implementation.

 

The int main( ) file I named Odd Or Even.cpp (The program determines whether two numbers are odd or even).

The header file I added to the program it holds the function prototype I named it MyLib.h

The additional .cpp file I added that holds the implementation I named it MyLib.cpp

 

I'm not too clear on the last file which C++ Builder generates when you create a new project. C++ Builder calls it PCH1.h. Here it is:

 

#ifdef _WIN32
#include <tchar.h>
#endif

bool isEven(int number);

But it seems like I have two function prototypes going on. One here in this PCH1.h file, and the other one in the MyLib.h file. I had to place the function prototype here because the compiler complained about an undeclared identifier without it. Then

I commented out the prototype in the MyLib.h file and rebuilt the project and it ran fine so I deleted that file.

 

But what is this PCH1.h file about with this code that automatically comes with it? PCH stands for what?

Edited December 30, 2024 by 357mag

[Roger Cigol 107]

PCH = pre compiled header. It's a file created at a full build by the compiler with the pure aim of speeding up compilation. In almost all cases you can just ignore it and let the compiler delete/recreate it as it needs to.

[Roger Cigol 107]

If you add a unit then the IDE adds both the *.cpp and .h files.

There can be cases where you have a .h file with no associated *.cpp file (and this is therefore not what the IDE calls a unit). 

In this case you can right click on the project name (= the exe file) in the project tree view and select add existing and navigate to the *.h file you want to add.

[Remy Lebeau 1440]

12 hours ago, 357mag said:

But what is this PCH1.h file about with this code that automatically comes with it? PCH stands for what?

C++ Precompiled Header File (*.pch)

 

Precompiled Headers Overview