Undefined local variable for hash in method ruby

Question

for some reason I\'m getting

NameError: undefined local variable or method `states\' for main:Object

though states is clearly defined. What

Answer 1

The method can't access the outside variables. You could use instance variables instead. From the documentation:

Instance variables are shared across all methods for the same object.

Example:

@states = {
  CA: 'California',
  FL: 'Florida',
  MI: 'Michigan',
  NY: 'New York',
  OR: 'Oregon',
}

@states[:CO] = 'Colorado'
@states[:HI] = 'Hawaii'

@cities = {
  CA: ['Alameda', 'Apple Valley', 'Exeter'],
  FL: ['Exeter', 'Amelia Island', 'Bunnell'],
  MI: ['Ann Arbor', 'East China', 'Elberta'],
  NY: ['Angelica', 'Apalachin', 'Canadice'],
  OR: ['Amity', 'Boring', 'Camas Valley'],
  CO: ['Blanca', 'Crestone', 'Dillon', 'Fairplay'],
  HI: ['Kailua', 'Hoopili', 'Honolulu'],
}

def describe_state state
  description = "#{state.to_s} is for #{@states[state]}."
  description << " It has #{@cities[state].length} major cities: "
  description << @cities[state].join(', ')
end

puts describe_state :CA
#=> CA is for California. It has 3 major cities: Alameda, Apple Valley, Exeter

(I've fixed a minor bug in describe_state)