You can create your custom header files in C; it helps you to manage user-defined methods, global variables, and structures in a separate file, which can be used in different modules.
A process to Create Custom Header File in C
For example, I am calling an external function named swap in my main.c file.
Example:
#include<stdio.h>
#include"swap.h"
void main()
{
int a=20;
int b=30;
swap (&a,&b);
printf ("a=%d\n", a);
printf ("b=%d\n",b);
}
The swap method is defined in the swap.h file is used to swap two numbers using a temporary variable.
Example:
void swap (int* a, int* b)
{
int tmp;
tmp = *a;
*a = *b;
*b = tmp;
}
Note:
- the header file name must have a .h file extension.
- In this example, I have named swap.h header file.
- Instead of writing <swap.h> use this terminology swap.h to include custom header file.
- Both files swap.h and main.c must be in the same folder.