```ruby
class Zipcode < ActiveRecord::Base
  belongs_to :county
  belongs_to :state

  validates :code, :uniqueness => true, :presence => true
  validates :state_id, :county_id, :city, :presence => true

  scope :without_county, -> { where("county_id IS NULL") }
  scope :without_state, -> { where("state_id IS NULL") }
  scope :ungeocoded, -> { where("lat IS NULL OR lon IS NULL") }

  class << self
    def find_by_city_state(city, state)
      includes(:county => :state).where("city like ? AND states.abbr like ?", "#{city}%", "%#{state}%").first
    end
  end

  def latlon
    [lat, lon]
  end

  def geocoded?
    (!lat.nil? && !lon.nil?)
  end
end
```

Change to Ruby 1.9+ hash syntax
user
```ruby
class Zipcode < ActiveRecord::Base
  belongs_to :county
  belongs_to :state

  validates :code, uniqueness: true, presence: true
  validates :state_id, :county_id, :city, presence: true

  scope :without_county, -> { where("county_id IS NULL") }
  scope :without_state, -> { where("state_id IS NULL") }
  scope :ungeocoded, -> { where("lat IS NULL OR lon IS NULL") }

  class << self
    def find_by_city_state(city, state)
      includes(county: :state)
        .where("city like ? AND states.abbr like ?", "#{city}%", "%#{state}%")
        .first
    end
  end

  def latlon
    [lat, lon]
  end

  def geocoded?
    (!lat.nil? && !lon.nil?)
  end
end
```
assistant