Your class with constructor, to string, setter, getter and inspect
class CD include Comparable @@plays = 0 attr_reader :name, :artist, :duration attr_writer :duration def initialize(name, artist, duration) @name = name @artist = artist @duration = duration @plays = 0 end def to_s "CD: #@name--#@artist (#@duration)" end def name @name end def artist @artist end def duration @duration end def duration=(new_duration) @duration = new_duration end def duration_in_minutes @duration/60.0 # force floating point end def duration_in_minutes=(new_duration) @duration = (new_duration*60).to_i end def play @plays += 1 # same as @plays = @plays + 1 @@plays += 1 "This CD: #@plays plays. Total #@@plays plays." end def record "Recording..." end def inspect self.to_s end def <=>(other) self.duration <=> other.duration end end