この壁に何瓶のビールがありますか？

Question

ruby​​-kickstartコースのクラスを作成するときに、私が最初に（そしてむしろばかげて）試みています。私newbish心の中で

が、これは動作するはずです - 代わりに私が手：

Class BeerSong 
attr_accessor :beers 

def initialize(beers) 
beers = 0 if beers < 0 
beers = 99 if beers > 99 
self.beers = beers 
end 


def print_song 
     bottlecount = :beers 

     letters_to_numbers = Hash.new 
     letters_to_numbers = { 
        "Ninety" => 90, 
        "Eighty" => 80, 
        "Seventy" => 70, 
        "Sixty" => 60, 
        "Fifty" => 50, 
        "Fourty" => 40, 
        "Thirty" => 30, 
        "Twenty" => 20, 
        "Nineteen" => 19, 
        "Eightteen" => 18, 
        "Seventeen" => 17, 
        "Sixteen" => 16, 
        "Fifteen" => 15, 
        "Fourteen" => 14, 
        "Thirteen" => 13, 
        "Twelve" => 12, 
        "Eleven" => 11, 
        "Ten" => 10, 
        "nine" => 9, 
        "eight" => 8, 
        "seven" => 7, 
        "six" => 6, 
        "five" => 5, 
        "four" => 4, 
        "three" => 3, 
        "two" => 2, 
        "one" => 1 
     } 

        while bottlecount > 1 
          bottlecount_primerA = bottlecount.to_s 
          bottlecount_primerB = bottlecount_primerA[0].to_i*10 
          bottlecount_primerC = bottlecount_primerA[1].to_i 

           if bottlecount > 19 && bottlecount_primerC != 0 
             bottlecount_tens = letters_to_numbers.key(bottlecount_primerB) 
             bottlecount_singels = letters_to_numbers.key(bottlecount_primerC) 
             bottlecount_text = "#{bottlecount_tens}-#{bottlecount_singels}" 
            elsif bottlecount > 19 && bottlecount_primerC == 0 
             bottlecount_tens = letters_to_numbers.key(bottlecount_primerB) 
             bottlecount_text = "#{bottlecount_tens}" 
            elsif bottlecount > 9 && bottlecount < 20 
             bottlecount_text = letters_to_numbers.key(bottlecount) 
           end 

          puts "#{bottlecount_text} bottles of beer on the wall," 
          puts "#{bottlecount_text} bottles of beer," 
          puts "Take one down, pass it around,"  
          bottlecount -= 1 
        end 
        puts "one bottle of beer on the wall," 
        puts "one bottle of beer," 
        puts "Take one down, pass it around," 
        puts "zero bottles of beer on the wall" 
end 

Bottleman = BeerSong.new (99) 

Bottleman.print_song 

はしばらくの間、私の頭を悩まれて28が "DEF print_songを" ですが、わからない：

rubytest.rb:28:in `<main>': uninitialized constant BeerSong (NameError) 

RBなぜクラスは行きたくないのですか？

Answer 1

はclass BeerSong誤っClass BeerSongとして入力されていますが、クラスが適切にendステートメントで終了されていないだけではなく。 Rubyは定義しようとしていることを理解するのではなく、BeerSongの定義を見つけようとします。見つからないと、初期化されていない定数エラーを返します。

これはRubyistsに正しい字下げを宗教的にさせるエラーの1種類なので、紛失endのようなものは見やすいものです。