Ruby hash - create element using an element which is being created within the hash

Question

Self descriptive non-working code:

mr_hash = {alpha: "hello", bravo: self.alpha + " world"} # Not working...

should give

{alpha: "hello", bravo: "hello world"}

Is it possible, and if so how, to do it within the hash? Without using intermediate variables like:

charlie = "hello"
delta = charlie + " world"
mr_hash = {alpha: charlie, bravo: delta}

Answer 1

Probably not what you're looking for but you can use Object#tap to avoid creating an additional variable:

mr_hash = Hash.new.tap do |h|
  h['alpha'] = 'Hello'
  h['bravo'] = h['alpha'] + ' world'
end
mr_hash # => {"alpha"=>"Hello", "bravo"=>"Hello world"}