benchmark string concat vs append vs +

benchmark_string_concat_append_+.rb

require 'benchmark/ips'

n = 100_000

Benchmark.ips do |x|
  x.config(time: 5, warmup: 2)

  x.report('concat') do |times|
    foo = ""

    n.times do |i|
      foo.concat("#{i}")
    end
  end

  x.report('append') do |times|
    foo = ""

    n.times do |i|
      foo << "#{i}"
    end
  end

  x.report('+') do |times|
    foo = ""

    n.times do |i|
      foo += "#{i}"
    end
  end

  x.compare!
end

Darwin mt-4.local 15.4.0 Darwin Kernel Version 15.4.0: Fri Feb 26 22:08:05 PST 2016; root:xnu-3248.40.184~3/RELEASE_X86_64 x86_64