benchmark_interpolation.rb

#!/usr/bin/env ruby
# encoding: utf-8

require 'benchmark'

iterations = 5_000_000

a = 'test a'
b = 'test b'
c = 'test c'

Benchmark.bmbm(15) do |bm|
  bm.report('a + b + c') do
    0.upto(iterations) do |i|
      a + " " + b + " " + c
    end
  end

  bm.report('interpolation') do
    0.upto(iterations) do |i|
      "#{a} #{b} #{c}"
    end
  end

  bm.report('[].join') do
    0.upto(iterations) do |i|
      [a, b, c].join(' ')
    end
  end
end

# Rehearsal ---------------------------------------------------
# a + b + c         2.060000   0.000000   2.060000 (  2.060781)
# interpolation     1.600000   0.000000   1.600000 (  1.604380)
# [].join           3.440000   0.000000   3.440000 (  3.443946)
# ------------------------------------------ total: 7.100000sec

# user              system     total      real
# a + b + c         2.070000   0.000000   2.070000 (  2.073246)
# interpolation     1.600000   0.000000   1.600000 (  1.599978)
# [].join           3.420000   0.010000   3.430000 (  3.422545)