Benchmark String interpolation vs Array#join

benchmark_interpolation_vs_join.rb

require 'benchmark'

def test_interpolation(x, y)
  "X#{x}Y#{y}"
end

def test_join(x, y)
  ["X", x, "Y", y].join
end

n = 100_000
Benchmark.bmbm(15) do |x|
  x.report("String interpolation")  { n.times { test_interpolation(1, 2) } }
  x.report("Array#join")            { n.times { test_join(1, 2)          } }
end

# >>                            user     system      total        real
# >> String interpolation   0.030083   0.000099   0.030182 (  0.030252)
# >> Array#join             0.080881   0.000200   0.081081 (  0.081173)