What will happen if I don't include header files

Question

What will happen if I don\'t include the header files when running a c program? I know that I get warnings, but the programs runs perfectly.

I know that the header f

Answer 1

There are a lot of things you can't do if you leave out headers:

(I'm hoping to get some more from the comments since my memory is failing on this ...)

• You can't use any of the macros defined in the headers. This can be significant.
• The compiler can't check that you are calling functions properly since the headers define their parameters for it.