ruby - 迭代一个常数是否是最佳实践？

Question

在我的 Ruby 脚本中，我在方法之外声明了一个常量:

SYNDICATIONS = %w(Advanced Syndication, Boxee feed, Player MRSS, iPad MRSS, iPhone MRSS, YouTube)

并以如下方法迭代它:

def some_method
   SYNDICATIONS.each do |syndication|
      puts syndication
   end
end

迭代一个常量是不是一个好主意？

Answer 1

迭代没有错。但是，常量的定义存在错误。 %w 运算符并不像您认为的那样工作。它在空格而不是逗号上拆分标记。如果您希望空格不是定界符，请将其转义。比较这三个例子，看看哪个最清楚。

a1 = %w(Advanced Syndication, Boxee feed, Player MRSS, iPad MRSS, iPhone MRSS, YouTube)
a1 # => ["Advanced", "Syndication,", "Boxee", "feed,", "Player", "MRSS,", "iPad", "MRSS,", "iPhone", "MRSS,", "YouTube"]

a2 = %w(Advanced\ Syndication Boxee\ feed Player\ MRSS iPad\ MRSS iPhone\ MRSS YouTube)
a2 # => ["Advanced Syndication", "Boxee feed", "Player MRSS", "iPad MRSS", "iPhone MRSS", "YouTube"]

a3 = ["Advanced Syndication", "Boxee feed", "Player MRSS", "iPad MRSS", "iPhone MRSS", "YouTube"]
a3 # => ["Advanced Syndication", "Boxee feed", "Player MRSS", "iPad MRSS", "iPhone MRSS", "YouTube"]