OpenEuphoria

Re: [OT] What is a 'header' file?

• Posted by Fernando Bauer <fmbauer at hotma?l.c?m> Jun 04, 2008
• 746 views

Matt Lewis wrote:
> 
> Derek Parnell wrote:
> > 
> > ZNorQ wrote:
> > > 
> > > I'm not quite sure what a header file is.
> > 
> > Header files are used by the C and C++ languages. 
> 
> <snip>
> 
> > Then, when the compiler comes across a reference to an object of the class
> > 'Bar',
> > it knows enough to check that the reference is valid.
> > 
> > Header files are useful for single pass compilers because it means that it
> > can
> > deal easily with forward references.
> > 
> > Header files are not needed for multiple pass compilers.
> 
> Yeah, but it's a bit more than that, because to build a C/C++ executable,
> compiling isn't enough.  Basically, the compiler compiles each .c/cpp/etc
> file into an object file, then it links them all together.  Before the
> linking,
> none of the object files really know about each other, except from what
> they've heard from header files.  Some of the references might also be
> resolved to dynamic/shared libraries.
> 
> Matt

Also, C header files help us to follow the "Don't Repeat Yourself" principle:
they can contain in one place symbols and macros declarations used by several
modules which form the program. Thus, the software creation and the software
maintenance is facilitated.

- Fernando