From: Wilhelm Date: 2006-10-11T22:05:07+09:00 Subject: Singleton classes and Singleton pattern I just happened upon singleton classes, and was wondering two things: 1) There's no difference between these two codes, right? Is there an advantage or disadvantage over either? Does Ruby put bar() into the same virtual class object for both? class Foo class << self def bar end end end class Foo def self.bar end end 2) A singleton class has nothing to do with the singleton design pattern, right? They only share the same name because there is only ever one of them.