Modules and Mixins

Question 1

Can modules be inherited? Can you create objects for the modules?

Answer 1

No, No

Question 2

What is the difference between #remove_method and #undef_method?

Answer 2

#undef_method( )
removes all methods, including the inherited ones.

#remove_method( )
removesall  the methods, incase of inheritance, it leaves inherited methods alone.

Question 3

Give the purpose of using modules?

Answer 3

Modules have 2 main purposes:
providing a namespace and prevent name clashes
using the mixin facility for composition

Question 4

Explain include keyword?

Answer 4

To do mixin we use include keyword

Question 5

Difference between prepend and extend keywords?

Answer 5

prepend keyword need object creation from class when 
being called.

Extend keyword don’t need object when being called

module Commentable
  def comment
    puts 'I love comments!'
  end
end

class Post
  extend Commentable
    def comment
    puts'I  comment!'
  end
end

Post.comment # I love comments!
#if its prepend keyword you need to do

Post.new.comment