Example using attr_accessor to transform data (variables) in messages (methods).

gistfile1.rb

class Artist
	#attr_accessor is ruby magic that transforms instance variables into reader & writer methods (see lines 14-22)  
	attr_accessor :name, :songs
	
	ARTISTS = []
	
	def initialize
	  @name = name
	  @songs = []
	  #for each instance of the class artist we instantiate(self), we push it into the ARTISTS array via the shovel method.
	  ARTISTS << self
	end
	
	#reader
	def name
	  @name
	end
	
	#writer
	def name=(name)
	  @name = name
	end
end

artist = Artist.new("Miss Piggy", ["Heeeee-YAH!"]) 
#by way of attr_accessor built in reader method, we can call name on an instance of the class artist to read the name.
puts artist.name
# => Miss Piggy
#likewise, via the attr_accessor's built in writer method, we can change artist's name at any time we want.
artist.name=("Prince")
puts artist.name
# => Prince