Adding User Input to a hash? Ruby

Question

I am trying to create some simple programs as trying to learn Ruby and then move on to rails, I am just playing about to try and get used to the flow of how different types of code work variables, loops etc.

I am trying to create a simple book system were I already have 3 books in my hash and then I want to list the books already in the library in the console and then I want to be able to add new books and then also loop through and display the new list to the console.

require 'rubygems'

class GetDetailsFromUser
  books = {
      Eagle_Eye: 1,
      Eage_Eye1: 2,
      Eagle_Eye2: 3
  }

  books.each do |i|
    puts i
  end

  while true
    add = gets.chomp
    break if add.empty?
    books << add
  end

  puts 'New list is below'

  books.each do |i|
    puts i
  end
end

Were am I going wrong? I manage to print out the hash to the console, however, I get an error message

undefined method '<<' for {:Eagle_Eye=>1,...

Why is the method undefined? books << add? This should add a new book to the book hash table?

JoeCodeCreations · Accepted Answer · 2016-04-07 13:13:03Z

2

Add your second number with it. Here is a working example I wrote for you

Live Demo - VISIT THIS LINK

  books = {
      Eagle_Eye: 1,
      Eage_Eye1: 2,
      Eagle_Eye2: 3
  }


      books.each do |i|
        puts i
      end

      while true
        puts "What book would you like to add?"
        add = gets.chomp
        if add.empty? == true
            puts "Error - You did not enter a title for a book"
            break
        else
        books.max_by do |book,id|
                 @list_number = id
                end
         books[add.to_sym]=@list_number
         break
        end
      end

  puts 'New list is below'

  books.each do |i|
    puts i
  end

answered Apr 7, 2016 at 13:13

JoeCodeCreations

6882 gold badges6 silver badges19 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Juan Manuel Rodulfo Salcedo · Accepted Answer · 2016-04-07 14:21:43Z

0

refactored version of @ExecutiveCloser

books = {
    Eagle_Eye: 1,
    Eage_Eye1: 2,
    Eagle_Eye2: 3
}

books.each do |i|
    puts i
end

add = ""

while add.empty? do
    puts "What book would you like to add?"
    add = gets.chomp

    books[add.to_sym] = books.size + 1 unless add.empty?
end

puts 'New list is below'

books.each do |i|
    puts i
end

https://repl.it/CDK2/3

answered Apr 7, 2016 at 14:21

Juan Manuel Rodulfo Salcedo

6191 gold badge4 silver badges13 bronze badges

Comments

Aleksei Matiushkin · Accepted Answer · 2016-04-07 12:17:34Z

0

Ruby has a documentation site. E. g. Hash documentation clearly states, that there is no method << defined on the hash instance.

<< method is defined on Array.

Why would you expect “books << add should add a new book to the book hash table”?

There is another glitch within your code: you execute everything on class definition level, which makes absolutely no sense in this case.

Since it is unclear what do you want to achieve, I am unable to provide a ready-to-go-with solution.

answered Apr 7, 2016 at 12:17

Aleksei Matiushkin

121k12 gold badges109 silver badges173 bronze badges

Collectives™ on Stack Overflow

Adding User Input to a hash? Ruby

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related