Variable naming
Ok, let's slow down and learn some basics about variable names
- Global variables start with '$'
- Class variables start with '@@'
- Instance variables start with '@'
- Local variables, method names, and method parameters start with a lower case letter
- Class names, module names and constants start with an uppercase letter
- Variables names are composed of letters, numbers and underscores
- Method names may end with "?", "!", or "=". Methods ending with a "?" imply a boolean operation (eg, "instance_of?"). Methods ending with "!" imply something dangerous, like strings being modified in place (eg, "upcase!")