order.rb

class Order
  def initialize
    @line_items = []
  end

  def add_line_item(line_item)
    @line_items << line_item
  end

  def total
    subtotals = @line_items.each { |li| li.quantity * li.price }
    subtotals.reduce(:+)
  end
end

class LineItem
  attr_reader :quantity, :price

  def initialize(quantity, price)
    @price    = price
    @quantity = quantity
  end
end

order = Order.new
order.add_line_item LineItem.new(2, 3.00)
order.add_line_item LineItem.new(4, 1.00)
puts order.total

Hi Benjamin,

I'm new to Ruby and still working through the basics. I'm also going through the Pry tutorial on http://www.sitepoint.com/rubyists-time-pry-irb/ ... does the Order object need to have "attr_accessor :line_items" in order for the line_item method to be shown when we do an "ls" when in the Order instance? Below is the output I get without the "attr_accessor" declaration.

marvin-mantes-macbook-pro:7253254 mante$ ruby -r pry order.rb

From: /Users/mante/Documents/App_Academy/Pry/7253254/order.rb @ line 12 Order#total:

10: def total
11:   subtotals = @line_items.each { |li| li.quantity * li.price }

=> 12: binding.pry
13: subtotals.reduce(:+)
14: end

[1] pry(#)> ls
Order#methods: add_line_item total
instance variables: @line_items
locals: _ __ dir ex file in out pry subtotals

Btw, thank you for the tutorial ... will be using Pry from here on out