In c to create a function which is not in the main source I should put the library I mean the # include...

Question

C

Answer 1

So to create a function we must put the library

Answer 2

We will #include<>, To access standard functions that are already implemented as a part of library.
Ex- printf() is a library function realized in 'stdio.h'. So, to access function '' printf() ", we shall put #include <stdio.h >