class Array
  def to_s
    self.join
  end
end

class Dog
  attr_reader :name

  def initialize(name)
    @name = name
  end

  def to_s
    "This good boy's name is #{name}!"
  end
end

fluffy = Dog.new(['F', 'l', 'u', 'f', 'f', 'y'])
puts fluffy # => "This good boy's name is Fluffy!"