How to change all the keys of a hash by a new set of given keys

Question

How do I change all the keys of a hash by a new set of given keys?

Is there a way to do that elegantly?

Answer 1

The exact solution would depend on the format that you have the new keys in (or if you can derive the new key from the old key.)

Assuming you have a hash h whose keys you want to modify and a hash new_keys that maps the current keys to the new keys you could do:

h.keys.each do |key|
  h[new_keys[key]] = h[key] # add entry for new key
  k.delete(key)             # remove old key
end