什么将输出给定的代码

Question

给出以下代码：

  class Book
    attr_accessor :author
    attr_reader :title
    attr_writer :comments
    def initialize(author, title)
      @author = author
      @title = title
      @comments = []
    end
  end

  book = Book.new("Chuck Palahniuk", "Fight Club")

以下哪些代码片段有效？

1.“＃{book.title}由＃{book.author}撰写。”

2.book.comments＆lt;＆lt; “＃{book.title}是一本好书”

book.comments.each {|评论|放评论}

book.title =“烹饪俱乐部”

Answer 1

答案是＃1 ......我如何获得巧克力？

#2 - There is no attr_accessor or attr_writer for comments
#3 - There is no attr_accessor or attr_reader for comments
#4 - There is no attr_accessor or attr_writer for title