DNA search program

dna.rb

class Dna
  # Prompt user for input.
  def pick_one
    puts "Enter DNA sequence. Must contain a, t, c, and g."
    input = gets.chomp
    process_input(input)
  end

  # Hash of dna sequences and values.
  # If input exists in hash, return value.
  # Else request input.
  def process_input(input)
    dna_pairs = {"atcg" => "Human", "gtca" => "Canine", "tgac" => "Feline", "ctga" => "Reptile"}
    if dna_pairs.has_key?(input)
      dna_pairs.each_pair do |key,value|
        if key == input
          puts value + " DNA sequence found."
        end
      end
    else
      pick_one
    end
  end
end
 
# Instantiate DNA object.
dna_choice = Dna.new
# Call input method on DNA object.
dna_choice.pick_one