我已经看过Ruby文档中有关struct，map，array和hash;的所有内容；但无论出于什么原因，都没有掌握如何做到这一点。我有两个问题。

1. 查看数组和哈希值是否具有共同值的好方法是什么？
2. 从哈希中，我如何找到一个值并“自动”获取它的键（反之亦然）并将其包含在其他事物的新实例中（例如Pair.new）？

我看到了这样的响应，但是并没有太大帮助。48

Zed表示也要使用地图功能，但也没有用。使用Ruby，最有效的方法是检查哈希中的任何键是否与Array中的任何值匹配

锻炼说明可以在这里找到。Ruby The Hard Way EX.48说明

我的密码（try＃2080）

class Lexicon

Pair = Struct.new(:token, :key)

def scan(stuff)
    @words = stuff.split(" ")
    return analyze
end

def analyze

    hash = { :direction => "north", :direction => "south", 
            :direction => "east", :direction => "west", :verb => "go",  
                                 :verb => "stop"}

    @words.map do |word|
        if word == hash[:direction]
        #i need something here that says if word matches a value in hash... 
        #assign matching key/value to a new instance of Pair
            Pair.new(word)
        else
                            *#puts to see if anything is sticking* 
            puts "Oh god its not working #{word}"
            puts Pair[]
            puts hash[:direction]
           end
       end
  end
end

a = Lexicon.new()
a.scan("north mama jeffrey homie")

终端

$ ruby lexicon.rb
Oh god its not working north
#<struct Lexicon::Pair token=nil, key=nil>
west

Oh god its not working mama
#<struct Lexicon::Pair token=nil, key=nil>
west

Oh god its not working Jeffrey
#<struct Lexicon::Pair token=nil, key=nil>
west

Oh god its not working homie
#<struct Lexicon::Pair token=nil, key=nil>
west

我的代码＃2081与上述相同，但是，

   hash.each do |k, v|
      if v == @words
      #i need something here that says if word matches a value in hash... 
      #assign matching key/value to a new instance of Pair
        Pair.new(k,v)
      else
        puts "Oh god its not working"
        puts Pair[]
        puts hash[:direction]
        puts @words
      end
   end

终端

Oh god its not working
#<struct Lexicon::Pair token=nil, key=nil>
...
...