Check if a hash's keys include all of a set of keys

Question

I\'m looking for a better way to do

if hash.key? :a &&
   hash.key? :b &&
   hash.key? :c &&
   hash.key? :d

prefer

Answer 1

You can get a list of missing keys this way:

expected_keys = [:a, :b, :c, :d]
missing_keys = expected_keys - hash.keys

If you just want to see if there are any missing keys:

(expected_keys - hash.keys).empty?