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

Just in the spirit of TIMTOWTDI, here's another way. If you require 'set' (in the std lib) then you can do this:

Set[:a,:b,:c,:d].subset? hash.keys.to_set