Different ways to discover what's true

vowels-etc.rb

#1
def is_vowel_elsif?(letter)
  if letter == "a"
    true
  elsif letter == "e"
    true
  elsif letter == "i"
    true
  elsif letter == "o"
    true
  elsif letter == "u"
    true
  else
    false
  end
end

#2
def is_vowel_case?(letter)
  case letter
  when "a" then true
  when "e" then true
  when "i" then true
  when "o" then true
  when "u" then true
  else false
  end
end

#3
def is_vowel_if?(letter)
  (["a","e","i","o","u"].each{|vowel| return true if letter==vowel}) == "WAT?"
end

#4
def one_line_is_vowel?(letter)
  letter=="a" || letter=="e" || letter=="i" || letter=="o" || letter=="u"
end

#5
def is_vowel_arr?(letter)
  vowels = ["a","e","i","o","u"]
  vowels.include?(letter)
end

#6
def first_vowel(str)
  str.scan(/a|e|i|o|u/).first
end

#7
def first_vowel_idx(str)
  vowel = first_vowel(str)
  str.index(vowel) if vowel != nil
end

lol! excellent use of == "WAT?" :D