acronomize.rb

# def acronymize(sentence)
#   string = ""
#   sentence.split(" ").each do |word|
#     string += word[0].upcase
#   end
#   return string
# end

# redo using map


# []  {} .

def acronymize(sentence)
  sentence.split(" ").map { |word| word[0].upcase }.join
end

acronomize_spec.rb

require_relative "../acronomize"

describe "#acronymize" do
  it "should return an empty string when passed an empty string" do
    actual = acronymize("")
    expected = ""
    expect(actual).to eq(expected) # passes if `actual == expected`
  end

  it "should return the acronym on upcase sentences" do
    actual = acronymize("FREQUENTLY ASKED QUESTIONS")
    expected = "FAQ"
    expect(actual).to eq(expected)
  end

   it "should return the acronym on downcase sentences" do
    actual = acronymize("hello world")
    expected = "HW"
    expect(actual).to eq(expected)
  end





  # write test "should return the acronym on upcase sentences"
  # for acronym("FREQUENTLY ASKED QUESTIONS") == "FAQ"

  # write test "should return the acronym on downcase sentences
  # write test for acronym("hello world") == "HW"
end

decrypt.rb

# modify encrypt so it can encrypt and decrypt using the same method
# and apply the permutation that we want, don't have to be 3

#  ||   []   {}   .  ;  :

def encrypt(text, num = -3)

  alphabet = ("A".."Z").to_a
  letters = text.upcase.split("")
  string = ""
  letters.each do |letter|
    index = alphabet.index(letter)
    if index.nil?
      string += letter
    else
      string += alphabet[(index + num) % 26]
    end
  end
  return string
end



def decrypt(text)
  # what code here
  encrypt(text, 3)
end

encrypted_text = "FK ZOVMQLDOXMEV, X ZXBPXO ZFMEBO, XIPL HKLTK XP ZXBPXO'P ZFMEBO, QEB PEFCQ ZFMEBO, ZXBPXO'P ZLAB LO ZXBPXO PEFCQ, FP LKB LC QEB PFJMIBPQ XKA JLPQ TFABIV HKLTK BKZOVMQFLK QBZEKFNRBP. FQ FP X QVMB LC PRYPQFQRQFLK ZFMEBO FK TEFZE BXZE IBQQBO FK QEB MIXFKQBUQ FP OBMIXZBA YV X IBQQBO PLJB CFUBA KRJYBO LC MLPFQFLKP ALTK QEB XIMEXYBQ. CLO BUXJMIB, TFQE X IBCQ PEFCQ LC 3, A TLRIA YB OBMIXZBA YV X, B TLRIA YBZLJB Y, XKA PL LK. QEB JBQELA FP KXJBA XCQBO GRIFRP ZXBPXO, TEL RPBA FQ FK EFP MOFSXQB ZLOOBPMLKABKZB."
puts decrypt(encrypted_text)

encrypt.rb

def encrypt(text)
  alphabet = ("A".."Z").to_a
  letters = text.upcase.split("")
  string = ""
  letters.each do |letter|
    index = alphabet.index(letter)
    if index.nil?
      string += letter
    else
      string += alphabet[index - 3]
    end
  end
  return string
end


# create method name encrypt that takes a parameter(string) called text

# create array containing alphabet

# split text in letters

# iterate on letters

# get index of letter

# check if index exists, if not return normal letter, if exist , apply rotation

# create string from array

puts encrypt("MethOd") == "JBQELA"