acronymize.rb

def acronymize(sentence)
  # create empty arrays of letters
  letters = []
  # separate the sentense into string
  words = sentence.split
  # iterate over words
  words.each do |word|
    # find the first letter of each word
    # send the letter to uppercase
    # add each letter to the array
    letters.push(word[0].upcase)
  end
  # transform array into string (.join)
  return letters.join
end

p acronymize("oh my god")

puts "", "Tests:"
puts acronymize("hello world").class == String
puts acronymize("oh my god") == "OMG"
puts acronymize("") == ""