encryptor.rb

class Encryptor

	def encrypt(string)
		letters = string.split("")

		results = []
		letters.collect do |letter|
			encrypted_letter = encrypt_letter(letter)
			results.push(encrypted_letter)
		end

		results.join
	end

	def encrypt_letter(letter)
		lowercase_letter = letter.downcase
		cipher[lowercase_letter]
	end

	def cipher
		{"a" => "n", "b" => "o", "c" => "p", "d" => "q",
     	"e" => "r", "f" => "s", "g" => "t", "h" => "u",
     	"i" => "v", "j" => "w", "k" => "x", "l" => "y",
     	"m" => "z", "n" => "a", "o" => "b", "p" => "c",
     	"q" => "d", "r" => "e", "s" => "f", "t" => "g",
    	"u" => "h", "v" => "i", "w" => "j", "x" => "k",
    	"y" => "l", "z" => "m"}
    end

    def decrypt(string)
    	letters = string.split("")

    	results = []
    	lettters.collecect
end