C Spot Run

The classic first C program is "Hello World."

#include <stdio.h>
main()
{
   printf("Hello World\n");
}

The first line includes a header file. Header files are used in C to define collections of things (what things we'll see later) that form libraries.

This particular library, (described by stdio.h ) is the Standard I/O Library. We'll see later that it defines the most common way in which data is inputted to and outputted from C programs.