ruby on rails - Link method argument to a variable -

i have program user able receive popular "vacation spots". al have enter continent (which bring them dictionary) , enter country/state (which key in hash) , find corresponding value.

i have required file (dict.rb) hash module using arrays.

but issue have small. assigned user input 2 variables, continent_select , country_select

here's code:

require './dict.rb'  #create new dictionary called northamerica northamerica = dict.new dict.set(northamerica, "new york", "new york city") dict.set(northamerica, "new jersey", "belmar")  puts "welcome vacation hub" puts "what continent interested in?" print '> '  continent_select = $stdin.gets.chomp.downcase  continent_select.gsub!(/\a"|"\z/, '')  puts "which state go in #{continent_select}" print '> '  country_select = $stdin.gets.chomp.downcase  #puts "you should go #{dict.get(northamerica, "#{country_select}")}" #=> should go belmar  puts "you should go #{dict.get(continent_select, "#{country_select}")}" #=> error 

ignore , set methods, they're in included dict.rb

anyway @ last few lines. dict.get method has 2 arguments. first finds dictionary use. if put northamerica argument works. if put continent_select instead (assuming user enters 'northamerica') doesn't work. think program looking dictionary named continent_select, rather looking variable continent_select.

update

here's whole dict.rb asked.

module dict     #creates new dictionary user     def dict.new(num_buckets=256)         #initializes dict given num of buckets         #creates adict variable empty array         #that hold our values later         adict = []          #loop through 0 number of buckets         (0...num_buckets).each |i|             #keeps adding arrays adict using push method             adict.push([])         end          return adict         #returns [[],[],[]] => array of empty arrays reading go.     end      def dict.hash_key(adict, key)         # given key create number , convert         # index adict's buckets.         return key.hash % adict.length         #key.hash makes key number         # % adict.length makes number between 1 , 256     end     def dict.get_bucket(adict, key)         #given key, find bucket go         #sets key number , it's put in bucket_id variable         bucket_id = dict.hash_key(adict, key)         #finds key number in dict, , returns key         return adict[bucket_id]     end     def dict.get_slot(adict, key, default=nil)         #returns index, key, , value of slot found in bucket         #assigns key name bucket variable         bucket = dict.get_bucket(adict, key)          bucket.each_with_index |kv, i|             k, v = kv             if key == k                 return i, k, v                 #returns index key found in, key, , value             end         end          return -1, key, default     end     def dict.get(adict, key, default=nil)         #gets value in bucket given key, or default         i, k, v = dict.get_slot(adict, key, default=default)         return v     end     def dict.set(adict, key, value)         #sets key value, replacing existing value         bucket = dict.get_bucket(adict, key)         i, k, v = dict.get_slot(adict, key)          if >= 0             bucket[i] = [key, value]         else             bucket.push([key, value])         end     end     def dict.delete(adict, key)         #deletes. given key dict         bucket = dict.get_bucket(adict, key)          (0...bucket.length).each |i|             k, v = bucket[i]             if key == k                 bucket.delete_at(i)                 break             end         end     end     def dict.list(adict)         #prints out what's in dict         adict.each |bucket|             if bucket                 bucket.each {|k, v| puts k, v}             end         end     end end 

now there's weird stuff going on.

in first case, seems okay, pass correct arguments:

dict.get(northamerica, "#{country_select}") 

that is: dict instance first argument, , string second. in second case:

dict.get(continent_select, "#{country_select}") 

you pass string instance instead of expected dict, , results in error.

as far understand intention, want user input become variable name used first argument, there no way way magically happening, , end passing string.

what need explicitly map user input corresponding dict object, , use it. can this:

# fetch dict object corresponds "northamerica" string hash # note: raise exception if user enters that's not present #       in hash, i.e. other "northamerica" selected_continent_dict = { "northamerica" => northamerica }.fetch(continent_select) puts "you should go #{dict.get(selected_continent_dict, country_select)}" 

if you're prohibited use ruby hashes, can away case statement:

selected_continent_dict = case continent_select   when "northamerica"     northamerica   else     raise "invalid continent"   end puts "you should go #{dict.get(selected_continent_dict, country_select)}" 

hope helps!

p.s. 2 more advice, if don't mind:

1. there's no real need string interpolation in second argument, , dict.get(northamerica, country_select) cleaner way.
2. better variable naming save headaches. i.e. if renamed (quite misleading) country_select user_state_selection_string remind string, , of holds. example arbitrary though. there's wonderful book called "code complete" steve mcconnell covers , other issues better do.