Benchmark that calculate the difference between regexp and start_with?

regexp_vs_start_with.rb

require 'benchmark'
require 'securerandom'

N = 1_000_000
REGEX = /^(abc|Abc|ABC)/

def gen_randstr(len = 24)
  SecureRandom.base64(len)
end

Benchmark.bm(13) do |x|
  x.report('start_with?') do
    N.times do
      gen_randstr.start_with?('abc', 'Abc', 'ABC')
    end
  end

  x.report('regex') do
    N.times do
      gen_randstr =~ REGEX
    end
  end
end

                    user     system      total        real
start_with?     0.879497   0.480250   1.359747 (  1.363121)
regex           0.854619   0.472788   1.327407 (  1.331010)