strings.rb

require 'benchmark'
n = 1_000_000
Benchmark.bmbm do |x|
  x.report("Double quotes") do
    n.times do
      str = "A simple string"
    end
  end

  x.report("Single quotes") do
    n.times do
      str = 'A simple string'
    end
  end

  x.report("evaled doube quotes") do
    n.times do
      eval(%q("hello world"))
    end
  end

  x.report("evaled single quotes") do
    n.times do
      eval(%q('hello world'))
    end
  end
end

# Rehearsal --------------------------------------------------------
# Double quotes          0.510000   0.000000   0.510000 (  0.513340)
# Single quotes          0.630000   0.000000   0.630000 (  0.645145)
# evaled doube quotes   19.400000   0.050000  19.450000 ( 19.496075)
# evaled single quotes  19.480000   0.040000  19.520000 ( 19.534261)
# ---------------------------------------------- total: 40.110000sec

#                            user     system      total        real
# Double quotes          0.510000   0.000000   0.510000 (  0.511511)
# Single quotes          0.510000   0.000000   0.510000 (  0.515970)
# evaled doube quotes   19.430000   0.040000  19.470000 ( 19.496095)
# evaled single quotes  19.570000   0.040000  19.610000 ( 19.670092)