String Concatenation and Addition
Copyright 1997 by John Lewis and William Loftus. All rights reserved.
The + operator serves two purposes
When applied to two strings, they are combined into one (string concatenation)
When applied to a string and some other value (like a number), that value is converted to a string and they are concatenated
When applied to two numeric types, they are added together arithmetically
See Antarctica.java and Sum.java