Ruby Benchmark: Starting a loop at index 1

loop_starting_at_index_one_benchmark.rb

# gem install benchmark-ips

require "benchmark/ips"

Benchmark.ips do |x|
  x.report("range") { (1..100).each { |i| i } }

  x.report("upto") { 1.upto(100).each { |i| i } }

  x.report("times plus one") { 100.times { |i| i + 1 } }

  x.report("times.with_index") { 100.times.with_index(1) { |_, i| i } }

  x.compare!
end

results

Warming up --------------------------------------
               range    14.417k i/100ms
                upto    10.648k i/100ms
      times plus one    11.611k i/100ms
    times.with_index     8.872k i/100ms
Calculating -------------------------------------
               range    152.190k (± 9.1%) i/s -    764.101k in   5.073210s
                upto    135.615k (± 7.4%) i/s -    681.472k in   5.056277s
      times plus one    132.532k (±13.2%) i/s -    661.827k in   5.140156s
    times.with_index     91.575k (± 9.3%) i/s -    452.472k in   5.005000s

Comparison:
               range:   152189.8 i/s
                upto:   135615.3 i/s - same-ish: difference falls within error
      times plus one:   132532.2 i/s - same-ish: difference falls within error
    times.with_index:    91575.2 i/s - 1.66x  slower