Use is_a? or instance_of?

Sunday, 09 May 2010 11:49

behaviour #-initialize-def-puts-fizzinitialize

Object#is_a? refers to a kind of class whereas Object#instance_of identifies the running Object's direct class.



class Behaviour

  def initialize

    puts 'Behaviour::initialize called'

  end

end



class Fizz < Behaviour

  def initialize

    puts 'Fizz::initialize called'

  end

end



b = Behaviour.new

#=> Behaviour::initialize called

b.is_a? Behaviour

#=> true



f = Fizz.new

#=> Fizz::initialize called

f.is_a? Behaviour

#=> true

f.instance_of? Fizz

#=> true

f.instance_of? Behaviour

#=> false

Resources:
- Class: Object [ruby-doc.org]