为什么我无法在 Ruby 中访问哈希？

Question

我打算将 Book1 的数据添加到散列 bl，但是当我运行代码时它会返回我

：在`booklist'中：参数数量错误（给定0，预期1）（ArgumentError）

这是我的代码。

class Book
  attr_accessor :title, :author, :language, :classification, :isbn, :book_id, :borrow_status



  def initialize(title, author, language, classification, isbn, book_id, borrow_status)
    @title = title
    @author = author
    @language = language
    @classification = classification
    @isbn = isbn
    @book_id = book_id
    @borrow_status = borrow_status
  end



  def booklist(bl)
     bl = {
    "Title " => @title.title.split(/ |\_|\-/).map(&:capitalize).join(" "),
    "Author " => @author.title.split(/ |\_|\-/).map(&:capitalize).join(" "),
    "Language " => (@language.title),
    "Classification " => @classification,
    "ISBN " => @isbn.to_s,
    "Book ID" => @book_id.to_s,
    "Status" => @borrow_status
    }
    end


  def put_booklist
    booklist.each do |x , y|
      puts "#{x}" , "#{y}"
    end
  end


end

books1 = Book.new("lonely planet: ireland","damian harper","english","tourism",9781786574459,1,"available")
books1.put_booklist

我想知道它有什么问题？

Answer 1

您的 booklist 方法需要一个参数，但在此调用中您没有传递任何参数

booklist.each do |x , y|

无论如何，根据booklist 的定义，您不需要也不需要使用该参数。将booklist移至

def booklist
  {
    "Title " => @title.title.split(/ |\_|\-/).map(&:capitalize).join(" "),
    "Author " => @author.title.split(/ |\_|\-/).map(&:capitalize).join(" "),
    "Language " => (@language.title),
    "Classification " => @classification,
    "ISBN " => @isbn.to_s,
    "Book ID" => @book_id.to_s,
    "Status" => @borrow_status
  }
end