These are generic notes made when i learnt the basics of Object Oriented programming using Ruby.

• Modules can reference public instance methods of the class, for e.g.

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module Walkable
  def walk
    "#{name} is walking"
  end
end

Class Dog
  attr_accessor :name
  include Walkable
  def initialize(n)
    @name = n
  end
end

The above will work ONLY if the class that implements the module Walkable has a public method name (which is a getter in this case). It is a good practice to put a comment to that effect where the module is defined.

• Only two things evaluate to the boolean false in Ruby, they are a null object nil and false

• Every expression returns something in Ruby. The return value is shown after an hash-rocket sign => in an IRB session after executing a line of code.

• It's a good idea to just return a string from a method and then using puts on the method call to display the desired string rather than doing a puts in the method itself.

• Exceptions in Ruby
• Raising exceptions during object instansiation

• A good way to start developing/design an OO application is following the steps below:
  1. Write the problem statement for the application
  2. Extract nouns from the problem statement: can be good indicators for required classes
  3. Extract verbs and associate them with the nouns: can be good indicators of required methods and responsibilities

Note: The above method was put to use here

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