Ruby in a Nutshell

Name

Constants

Synopsis

Foo

Constants begin with an uppercase letter. Constants defined within a class or module can be accessed from within that class or module, and those defined outside a class or module can be accessed globally. Constants may not be defined within methods. Referencing an uninitialized constant produces an error. Making an assignment to a constant that is already initialized produces a warning, not an error. You may feel it contradicts the name “constant,” but remember, this is listed under “variables.”