How do I create a Class using the Singleton Design Pattern in Ruby? - Stack Overflow

The singleton pattern is a design pattern that is used to restrict instantiation of a class to one object instance. Although I know how to code the singleton pattern in C++ and Java, I was wondering if anyone know how to implement it in Ruby?

Answers：

The singleton pattern is a design pattern that is used to restrict instantiation of a class to one object instance. Although I know how to code the singleton pattern in C++ and Java, I was wondering if anyone know how to implement it in Ruby?

Answers：

Actually, the above answer was not completely correct.

require 'singleton'

class Example
  include Singleton
end

You also need to include the require 'singleton' statement.

Answers：

Use the singleton module:

class Clazz
  include Singleton
end

See http://www.ruby-doc.org/stdlib/libdoc/singleton/rdoc/index.html for more info.

Answers：

You could use modules to the same effect I believe, although its not "the singleton pattern" you can have global state that way (which is what a singleton is ! Naughty global state !).