How to elegantly rename all keys in a hash in Ruby? [duplicate]

Answer 1

You may wish to use Object#tap to avoid the need to return ages after the keys have been modified:

ages = { "Bruce" => 32, "Clark" => 28 }
mappings = {"Bruce" => "Bruce Wayne", "Clark" => "Clark Kent"}

ages.tap {|h| h.keys.each {|k| (h[mappings[k]] = h.delete(k)) if mappings.key?(k)}}
  #=> {"Bruce Wayne"=>32, "Clark Kent"=>28}