Question

I want to compare the keys in a hash of parameters against an array of elements for a match.

For example:

params          = {"key1", "key2", "key3"}
params_to_match = ["key2","key3"]

I could do this, but I’m sure there is a much more elegant way to acheive the same result

params.each_key{|key|
  if params_to_match.include?(key.to_s)
    return
  end
}

Answer 1

Not necessarily more efficient but perhaps more elegant in some sense:

return unless (params.keys & params_to_match).empty?

A more efficient way than your example would (in the general case, not necessarily with such a small toy example) be to check whether the hash contains the keys, since the time to look those up is practically constant while looking them up from the array is O(n). So, your example would become something like this:

params_to_match.each { |p| return if params.has_key?(p) }