键映射到多个值 [英] Key mapping to multiple values

问题描述

在Ruby中，我想拥有类似于

  my_hash = {：a => [b，c，h]，：d => [e，f，g] ..} 
  

而不是
my_hash = {：a => b，：a => c，：a => h，：d => e，：d => f，：d => g} 。
我不能使用数组作为值，因为我想获取值的关键字，例如
my_hash.key（c）应该返回一个值。
有没有人知道如何用ruby hash类来做到这一点，或者是否有任何其他数据结构。
谢谢。

解决方案

  class Hash 
 def key_array_with（val）
 self.keys.select {| k | k.include？（val）} .first 
 end 
 end 
 
 h = {[：b，：c，：h] => ：a，[：e，：f，：g] => ：d} 
 h [h.key_array_with（：c）] 
  

In Ruby, I want to have something like

my_hash =  {:a => [b,c,h], :d => [e,f,g]..}

instead of my_hash= {:a => b ,:a => c ,:a => h , :d => e , :d=> f ,:d => g }. I cannot use arrays as value because I want to get the key of the value ie my_hash.key(c) should return a . Does any body know how to do this with ruby hash class or is there any other data structure. Thanks.

解决方案

Reversing the hash is probably your best bet but, heh, just for kicks...

class Hash
  def key_array_with(val)
    self.keys.select { |k| k.include?(val) }.first
  end
end

h = {[:b,:c,:h] => :a, [:e,:f,:g] => :d}
h[h.key_array_with(:c)]

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