Fast way to create a class dynamically and add methods to it.

create_class_and_method.rb

# Creating the class
class_reference = Object.const_set 'Shalalala', Class.new(Array) # Array will be setted as the superclass for Shalalala. Neat, ha?

# defining a method
class_reference.class_eval do 
  define_method :my_method, proc { puts 'hello' }
end

# See for yourself
instance = class_reference.new
instance.my_method # => 'hello'

# Most interestingly, the class was defined in the constant so can be referenced anywhere
Shalalala.new.my_method # => 'hello'