Question

我做到了这一点，但不知道在哪里添加.to_i和.to_sym方法，因为我假设我把它们放在错误的地方。有人可以帮我吗？当我测试代码时，它说“未定义的方法`to_sym ='代表nil：NilClass”

movies = { 
  spiderman: 3,
  superman: 4,
  batman: 5
}

puts "what movie do you like?"
choice = gets.chomp

case choice
when 'add'
puts "What movie do you want to add?"
title.to_sym = gets.chomp
puts "what is the rating of that movie?"
rating.to_i = gets.chomp
movies[title]=rating
puts "Added!"

when 'update'
    puts "What movie would you like to update?"
    title = gets.chomp
    puts "Updated!"
when 'display'
    movies.each do |movies, ratings|
    puts "#{movies}: #{ratings}"
    end

    puts "Movies!"
when 'delete'
    puts "What movie would you like to delete from the list?"
    title = gets.chomp
    puts "Deleted!"

else 
    puts "Error!"
end

Answer 1

除了[]=之外，没有形式foo=或to_sym=的方法，就像你的代码中的普通Ruby一样。如果要将用户输入作为符号，可以执行以下操作：

title = gets.chomp.to_sym

如果你想得到一个整数，你可以这样做：

rating = gets.to_i

我不知道为什么在后一种情况下你有chomp。

在Ruby中我的哈希中将字符串转换为符号和整数

1 个答案: