concatenate-vs-join.rb

require 'benchmark/ips'

STRINGS = %w[
  There's no beginning to this story. A bookshelf sinks into the sand. And a
  language learned, a forgotten term, is studied once again. It's a shocking
  bit of footage viewed from a shitty TV screen. Just squint at it, just snowy
  static to make out the meaning. And keep on stretching the antenna hoping that
  it will come clear. We need some reception, a higher message. Just tell us
  what to fear 'cause I don't know what tomorrow brings. It's alive with such
  possibility. All I know is I feel better when I sing.
]

def concatenate
  STRINGS.inject('') {|memo, string| memo + string}
end

def join
  STRINGS.join
end

Benchmark.ips do |x|
  x.report('Concatenate') { concatenate }
  x.report('Join')        { join }
  x.compare!
end

output.txt

Calculating -------------------------------------
         Concatenate     2.753k i/100ms
                Join    17.199k i/100ms
-------------------------------------------------
         Concatenate     28.549k (± 5.6%) i/s -    143.156k
                Join    200.620k (± 4.9%) i/s -      1.015M

Comparison:
                Join:   200620.3 i/s
         Concatenate:    28548.9 i/s - 7.03x slower