为什么我不能从散列中读取值？ [英] Why can't I read a value from a hash?

问题描述

考虑以下代码：

  hash = {a=> [B，C] ，b=> [C]，c=> [D，E]，d=> [F]} 
 puts hash [a ] 
  

这只是不打印任何东西。

  puts hash [a]。class 
  

打印 NilClass

是否有某种已知的错误在下面的ruby版本中？

ruby​​ 2.0.0p247（2013-06-27 revision 41674）[universal.x86_64-darwin13] p>

我希望有人能帮助我，这让我疯狂。我的IDE是JetBrains的RubyMine。我也尝试通过IRB直接运行它。

谢谢

PS。 OS是OSX

解决方案

通过复制代码并将其粘贴到我的控制台中，我可以重现您的问题。 b
$ b

然后我把你的散列做了以下操作：

  hash.first.first 
＃=> a
 hash.first.first.length 
＃=> 2 
  

!!!

看来你的a有一个不可打印的第一个字符。删除它，你会没事的。

你的字符是这是什么字符？ 65279''：

  hash.first.first [0] .ord 
＃=> 65279 
  

Considering the following code:

  hash = {"a"=>["B", "C"], "b"=>["C"], "c"=>["D", "E"], "d"=>["F"]}
  puts hash["a"]

This just prints nothing.

puts hash["a"].class

This prints NilClass

Is there some kind of known bug in the following ruby version?

ruby 2.0.0p247 (2013-06-27 revision 41674) [universal.x86_64-darwin13]

I hope someone can help me out, this is driving me crazy. My IDE is RubyMine from JetBrains. I also tried to run it directly via IRB.

Thanks

PS. OS is OSX

解决方案

By copying your code and pasting it in my console, I could reproduce your problem.

Then I took your hash and did the following:

hash.first.first
# => "a"
hash.first.first.length
# => 2

!!!

It seems that your "a" has an unprintable first char. Delete it, and you'll be fine.

And you char is What is this char? 65279 '':

hash.first.first[0].ord
# => 65279

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