Hello, all! This exercise is from Zed Shaw's Learn Ruby the Hard Way, and there are a few points that seem mysterious. On line 22, it seems that a hash object is calling a method ".call" with two arguments, the original hash, and a string the user has entered. I know the code works, and I know the code can be simpler. I'm just wondering what sor…

hash_ex.rb

cities = {'CA' => 'San Francisco', 'MI' => 'Detroit', 'FL' => 'Jacksonville'}

cities['NY'] = 'New York'
cities['OR'] = 'Portland'

def find_city(map, state)
  if map.include? state
    return map[state]
  else
    return "Not found."
  end
end

cities[:find] = method(:find_city)

while true
  print "State? (Enter to quit) "
  state = gets.chomp

  break if state.empty?

  puts cities[:find].call(cities, state)
end