How to replace a hash key with another key

Question

I have a condition where, I get a hash

  hash = {\"_id\"=>\"4de7140772f8be03da000018\", .....}

and I want this hash as

Answer 1

Previous answers are good enough, but they might update original data. In case if you don't want the original data to be affected, you can try my code.

 newhash=hash.reject{|k| k=='_id'}.merge({id:hash['_id']})

First it will ignore the key '_id' then merge with the updated one.