Sort hash by key, return hash in Ruby

Question

Would this be the best way to sort a hash and return Hash object (instead of Array):

h = {\"a\"=>1, \"c\"=>3, \"b\"=>2, \"d\"=>4}
# => {\"a\"=         


        

Answer 1

No, it is not (Ruby 1.9.x)

require 'benchmark'

h = {"a"=>1, "c"=>3, "b"=>2, "d"=>4}
many = 100_000

Benchmark.bm do |b|
  GC.start

  b.report("hash sort") do
    many.times do
      Hash[h.sort]
    end
  end

  GC.start

  b.report("keys sort") do
    many.times do
      nh = {}
      h.keys.sort.each do |k|
        nh[k] = h[k]
      end
    end
  end
end

       user     system      total        real
hash sort  0.400000   0.000000   0.400000 (  0.405588)
keys sort  0.250000   0.010000   0.260000 (  0.260303)

For big hashes difference will grow up to 10x and more