Rubyの練習。99 Bottles of Beerです。

99-bottles-of-beer.rb

def bottles_of_beer(n)
  def bottle(n)
    bottles = case n
      when 0
        "No more bottles"
      when 1
        "#{n} bottle"
      else
        "#{n} bottles"
    end
  
    "#{bottles} of beer"
  end

  def take_down(n)
    if n > 0 then
      "Take one down and pass it around"
    else
      "Go to the store and buy some more"
    end
  end

  n.downto(0) do |i|
    s = <<-"eos"
#{bottle i} on the wall, #{bottle i}.
#{take_down i}, #{bottle i == 0 ? n : i - 1} on the wall.
    eos

    if block_given? then
      yield s
    else
      puts s + "\n"
    end
  end
end

bottles_of_beer(99)