# create a mapping of state to abbreviation
states = {
  "Oregon" => "OR",
  "Florida" => "FL",
  "California" => "CA",
  "New York" => "NY",
  "Michigan" => "MI"
}

# create a basic set of states and some cities in them
cities = {
  "CA" => "San Francisco",
  "MI" => "Detroit",
  "FL" => "Jacksonville"
}

# add some more cities
cities["NY"] = "New York"
cities["OR"] = "Portland"

# puts out some cities
puts "-" * 10
puts "NY State has: #{cities["NY"]}"
puts "OR State has: #{cities["OR"]}"

# do it by using the state then cities dict
puts "-" * 10
puts "Michigan has: #{cities[states["Michigan"]]}"
puts "Florida has: #{cities[states["Florida"]]}"

# puts every city in state
puts "-" * 10
cities.each do |abbrev, city|
  puts "#{abbrev} has the city #{city}"
end

# now do both at the same time
puts "-" * 10
states.each do |state, abbrev|
  city = cities[abbrev]
  puts "#{state} is abbreviated #{abbrev} and has city #{city}"
end

puts "-" * 10
# by default ruby says "nil" when something isn't in there
state = states["Texas"]

if !state
  puts "Sorry, no Texas."
end

# default values using ||= with the nil result
city = cities["TX"]
city ||= "Does not exist"
puts "The city for state 'TX' is: #{city}"