Notes

Everything that goes on under the hood of a computer is done in binary -- the language of 0s and 1s. In order to use binary to express alphabetic, numeric, and other characters, we need some kind of mapping between characters and numbers.

ASCII is an encoding system that maps alphabetic, numeric, and other characters to numbers. For example, uppercase 'A' is represented by the number 65, and lowercase 'a' is represented by the number 97.

The following will print out: 32 b B C a

This program will print the uppercase letters of the alphabet in reverse alphabetical order. Note how you can use 'Z' instead of the magic number 90, and 'A' instead of the magic number 65. Definitely makes the code more readable!