hash.each_vs_hash.values.each.rb

require 'benchmark'

n = 1_000_000
h = {:a => {'a' => 'A'}, :b => {'b' => 'B'}}

puts %Q{
  h.each {|kv| kv[1]}
  
}
Benchmark.benchmark do |bm|
  4.times do
    bm.report do
      n.times do
        h.each {|kv| kv[1]}
      end
    end
  end
end

puts %Q{
  h.values.each {|kv| kv}
  
}
Benchmark.benchmark do |bm|
  4.times do
    bm.report do
      n.times do
        h.values.each {|kv| kv}
      end
    end
  end
end

results.txt

h.each {|kv| kv[1]}
  
1.390000   0.010000   1.400000 (  1.431899)
1.390000   0.010000   1.400000 (  1.420193)
1.380000   0.000000   1.380000 (  1.393531)
1.380000   0.000000   1.380000 (  1.422122)

h.values.each {|kv| kv}

1.150000   0.010000   1.160000 (  1.154314)
1.140000   0.000000   1.140000 (  1.160401)
1.150000   0.000000   1.150000 (  1.157688)
1.140000   0.000000   1.140000 (  1.158936)