来自Rails 4中具有匹配数组值的哈希的所有键

Question

I have a hash such as:

CHAR_MAP = {
  :x => %w[something]
  :y => %w[something2 something]
  :z => %w[something3 something1]
  :r => %w[something something3]
  ...
  ...
}

And I have another array

x = ['something', 'something3']

Now for the hash CHAR_MAP I want a list of keys for which all the values in it's corresponding value array are a part of the array x

So for array x we should get the keys x and r as output

@recommendation_factors.each do |rf|
  @rec_list = CHAR_MAP.detect{|h| h == rf.recommendation_factor}
end

I tried the above but it keeps on returning an empty array. :/

Answer 1

试试这个

CHAR_MAP.keys.select { |k| (CHAR_MAP[k] - x).empty? }