Change all key names in a hash to numbered names (0, 1, 2, 3…)

Question

I need to change the key names of a hash to numbered names. Eg

hash = {"0"=>["val", "val"], "1"=>["val"], "6"=>["val", "val"], "7"=>["val"]}

into

hash = {"0"=>["val", "val"], "1"=>["val"], "2"=>["val", "val"], "3"=>["val"]}

The numbering will start at zero and continue until the end of the hash. The hash length will be random.

Answer 1

new_hash = hash.values.map.with_index { |value, idx| [idx.to_s, value] }.to_h
#=> {"0"=>["val", "val"], "1"=>["val"], "2"=>["val", "val"], "3"=>["val"]}

Answer 2

key = -1

Hash[hash.map { |_,v| [(key = key.next).to_s, v] }]

or

hash.map { |_,v| [(key = key.next).to_s, v] }.to_h