的Ruby/Rails - 與未定義的方法錯誤加盟

Question

我通過努力環和匹配以下字符串：

@custom_channels = { cnn: 2, abc: 90 } 

話，我希望能夠檢查/對陣每返回頻道號（例如，90）：

listen_for /channel to (#{@custom_channels.join('|')})/i do |name| 
    change_channel @custom_channels[name.downcase] 
end 

我不斷收到以下錯誤：

scraper.rb:5:in `<main>': undefined method `join' for {:cnn=>2, :abc=>90}:Hash (NoMethodError) 

Answer 1

如果我明白你問什麼：

@custom_channels = { cnn: 2, abc: 90 } 

channel_names = @custom_channels.keys.map(&:to_s) 

listen_for /channel to (#{Regexp.union(channel_names)})/i do |name| 
    change_channel @custom_channels[name.to_sym] 
end 

Answer 2

試試這個：

1.9.3p0 :007 > channels = {:cnn=>2, :abc=>90} 
=> {:cnn=>2, :abc=>90} 
1.9.3p0 :008 > channels.keys 
=> [:cnn, :abc] 
1.9.3p0 :009 > channels.keys.each do |name| 
1.9.3p0 :010 >  puts channels[name] 
1.9.3p0 :011?> end 
2 
90 
=> [:cnn, :abc]