Ruby benchmark: Array#each vs for x in array

each_benchmark.rb

#!/usr/bin/env ruby -w
require "benchmark"

TIMES = 100_000
ARRAY = (1..1_000).to_a

Benchmark.bm(30) do |b|
  b.report "each" do
    TIMES.times do |i|
      ARRAY.each do |element|
      end
    end
  end

  b.report "for ... in" do
    TIMES.times do |i|
      for x in ARRAY
      end
    end
  end
end

__END__
                                    user     system      total        real
each                            9.710000   0.010000   9.720000 (  9.740620)
for ... in                      7.460000   0.000000   7.460000 (  7.475158)

ruby 3.2.1 (2023-02-08 revision 31819e82c8) [x86_64-linux]

                                     user     system      total        real
each                             2.052966   0.000207   2.053173 (  2.053209)
for ... in                       2.225467   0.000006   2.225473 (  2.225489)
for ... in 0..limit              2.478339   0.000000   2.478339 (  2.478365)
while i <ARRAY.size              1.727570   0.000000   1.727570 (  1.727601)
while i <limit                   1.469423   0.000001   1.469424 (  1.469439)

ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x64-mingw-ucrt]

                                   user     system      total        real
each                             4.203000   0.000000   4.203000 (  4.222868)
for ... in                       4.562000   0.000000   4.562000 (  4.583148)
for ... in 0..limit              5.047000   0.000000   5.047000 (  5.050032)
while i <ARRAY.size              2.219000   0.000000   2.219000 (  2.235048)
while i <limit                   1.984000   0.000000   1.984000 (  2.017428)