loop_benchmark.rb

require 'benchmark'

max = (ARGV.shift || 10_000_000).to_i

puts "# of iterations = #{max}"
Benchmark::bm(20) do |x|
  x.report("each") do
    (0..max).each do
    end
  end

  x.report("for") do
    for i in 0..max do
      # do nothing
    end
  end

  x.report("each-var") do
    (0..max).each do |i|
    end
  end

  x.report("while") do
    n = 0
    while true do
      break if n >= max
      n += 1
    end
  end

  x.report("loop") do
    n = 0
    loop do
      break if n >= max
      n += 1
    end
  end

  x.report("begin") do
    n = 0
    begin
      n += 1
    end while(n < max)
  end
end