A C program to demonstrate the uses of:
Variables (static, external): Integers, Floating point numbers, Characters, Arrays, Character Arrays (strings). Enumerators, printf(); function, Mathematical operations, type casting.
In order to demonstrate the uses and applications of each of these a program, which uses each, should be produced providing output for the user to see.
Without using functions/procedures other than main ();
Initially demonstrate the use of printf(); with 'Hello World'.
Initialise each variable type (so far) with a value and use printf(); to display these values.
Comment each printf(); to show readers what it is used for.
Demonstrate a simple use of Enumerators.
Extensively comment on the code to explain what is happening and when.
You are welcome to download this program's code should you wish to run it.

Syntax highlighting thanks to
C/C++ Program 1
Example Output:

Screenshot of C/C++ Program 1
Screenshot of C/C++ Program 1
Thanks to Shirley Williams for spotting my initial mistake of not casting a conversion correctly.