Happy OOP examples using Ruby

happy_oop.rb

#These Ruby OOP examples, are based on the Rails 3 presentation by @guilhermecaelum
class Person
  #the attribute name is immutable 
  def initialize(name)
    @name = name
  end
  def name
    @name
  end
end
pablo = Person.new('Pablo')
puts "pablo.name = #{pablo.name}"
#output
#pablo.name = Pablo

#overrides the method name only for the class INSTANCE scope
def pablo.name 
  @name.upcase
end
puts "pablo.name = #{pablo.name}"
#output
#pablo.name = PABLO

#overrides method name for the class scope
class Person
  def name
    @name.downcase
  end
end
cantero = Person.new('Cantero')
puts "cantero.name = #{cantero.name}"
#output
#cantero.name = cantero

#YES... you also can change core classes like others classes
class String
  #Added to_mussum for all strings instances
  def to_mussum
    self + 'zis'
  end
end
puts 'Calcida'.to_mussum
#output
#Calcidazis

#'Multiple inheritance'
module Horse
   def run
     puts 'Inhhhhriiiii'
   end
end
module Bird
   def fly
     puts 'Briiiihhhhh'
   end
end
class Pegasus
   include Horse
   include Bird
end
pegasus = Pegasus.new
pegasus.run
pegasus.fly
#output
#Inhhhhriiiii
#briiiihhhhh