foo.rb

class Hero
  attr_reader :items

  def initialize(items)
    @items = {
      'crude sword' => 0,
      'Armour' => 0,
      'Helmet' => 0,
    }

    items.each do |item|
      item.strip!
      items[item] += 1 if items[item]
    end
  end
end

items = File.readlines("foo.txt")
player = Hero.new(items)
p player.items