gistfile1.rb

require "rubygems"
require "benchmark"

def setup_array
  array = []
  10_000_000.times { array << rand }
  array
end

def modulo(step_size)
  array   = setup_array
  result  = []
  
  Benchmark.measure do
    array.each_with_index do |element, index|
      result << element if index % step_size == 1
    end
  end
end

def step(step_size)
  array   = setup_array
  result  = []
  
  Benchmark.measure do
    (0..array.length - 1).step(step_size).each do |index|
      result << array[index]
    end
  end
end


puts "modulo, step_size = 2: #{modulo(2)}"
puts "step, step_size = 2: #{step(2)}"

puts "modulo, step_size = 1_000_000: #{modulo(1_000_000)}"
puts "step, step_size = 1_000_000: #{step(1_000_000)}"




# modulo, step_size = 2:   7.940000   0.100000   8.040000 (  8.043250)
# step, step_size = 2:   2.050000   0.030000   2.080000 (  2.075453)
# modulo, step_size = 1_000_000:   7.040000   0.090000   7.130000 (  7.118047)
# step, step_size = 1_000_000:   0.000000   0.000000   0.000000 (  0.000024)