Programming on the Wall

Objects, classes, inheritance, polymorphism- it sounds a little like Biology, and in some ways, object oriented programming (OOP) mirrors the natural world.  I've finally reached the OOP section in the Odin Project's Ruby Programming course. Many of the concepts are straightforward-especially to anyone who has read a little philosophy or studied evolutionary biology. The difficult part is translating the concepts into actual functioning OOP applications.  I've started reading what looks to be a promising book on OOP design in Ruby. I've learned something already that may improve my code. Here's an example from chapter 2:  class Gear    attr_reader :chainring, :cog,     def initialize(chainring, cog)      @chainring = chainring      @cog = cog    end    def ratio      (chainring / cog.to_f).round(2)    end end This is the 'good' way to create a class....