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

I like this way to solve this:

subset = [:a, :b, :c, :d]
subset & hash.keys == subset

It is fast and clear.