我正在完成codecademy练习,我无法弄清楚.nil是什么？意味着我需要实施它.这是我的代码:
movies = { GIS: 10.0, Phantasm: 1.5, Bourne: 4.0}
puts "Whats your movie brah?"
title = gets.chomp
puts "What's your rating brah?"
rating = gets.chomp
movies[title] = rating
puts "Your info was totally saved brah!"
case movies
when 'add'
puts "What movie do you want to add?"
title = gets.chomp
if movies[title.to_sym].nil?
puts "What's the rating? (Type a number 0 to 4.)"
rating = gets.chomp
movies[title.to_sym] = rating.to_i
puts "#{title} has been added with a rating of #{rating}."
else …