Funky Ruby Class Method Syntax

I’ve run across this syntax a few different times but never grasped how it worked, and I guess never cared enough to look it up. Turns out it’s dead simple.

This:

class Person  
  def self.species
    "Homo Sapien"
  end
end

is equivalent to this:

class Person  
  class << self
    def species
      "Homo Sapien"
    end
  end
end

Thanks to Yehuda Katz for finally clearing that up for me.