Module

A Module is a collection of methods and constants. The methods in a module may be instance methods or module methods. Instance methods appear as methods in a class when the module is included, module methods do not. Conversely, module methods may be called without creating an encapsulating object, while instance methods may not. (See Module#module_function)

In the descriptions that follow, the parameter syml refers to a symbol, which is either a quoted string or a Symbol (such as :name).

   module Mod
     include Math
     CONST = 1
     def meth
       #  ...
     end
   end
   Mod.class              #=> Module
   Mod.constants          #=> ["E", "PI", "CONST"]
   Mod.instance_methods   #=> ["meth"]