In Swift, you have to signal and guard against the nil. In ruby, you choose whether to signal and you choose whether to guard. Here are some ruby examples that

In Swift, you have to signal and guard against the nil. In ruby, you choose whether to signal and you choose whether to guard. Here are some ruby examples that may be more clear: Does not signal user = User.find_by_favorite_dinosaur("Dromiceiomimus") Does not guard def print_favorite_dinosaur(user) p "User's favorite dinosaur is #{user.dino})" end Signals and guards def print_favorite_dinosaur(user) if user p "User's favorite dinosaur is #{user.dino})" else p "No user. (Let's assume she likes T-rexs)" end end possible_user = User.find_by_favorite_dinosaur("Dromiceiomimus") print_favorite_dinosaur(possible_user)