newline.rb

require 'benchmark'
n = 1_000_000
s = "a b c d e f g h"
Benchmark.bmbm do |x|
  x.report("Scan (regexp)")      { n.times { s.scan(/h/).empty? } }
  x.report("Scan (string)")      { n.times { s.scan("h").empty? } }
  x.report("Include")   { n.times { s.include?("h") } }
  x.report("=~")        { n.times { s =~ /h/} }

  x.report("Scan (regexp) (not findable)")      { n.times { s.scan(/i/).empty? } }
  x.report("Scan (string) (not findable)")      { n.times { s.scan("i").empty? } }
  x.report("Include (not findable)")   { n.times { s.include?("i") } }
  x.report("=~ (not findable)")        { n.times { s =~ /i/} }
end

# Rehearsal ----------------------------------------------------------------
# Scan (regexp)                  4.710000   0.010000   4.720000 (  4.726882)
# Scan (string)                  6.420000   0.020000   6.440000 (  6.445207)
# Include                        0.870000   0.000000   0.870000 (  0.866947)
# =~                             1.100000   0.000000   1.100000 (  1.100991)
#
# Scan (regexp) (not findable)   1.750000   0.010000   1.760000 (  1.758479)
# Scan (string) (not findable)   2.620000   0.000000   2.620000 (  2.642941)
# Include (not findable)         0.830000   0.000000   0.830000 (  0.840811)
# =~ (not findable)              1.040000   0.010000   1.050000 (  1.061319)
# ------------------------------------------------------ total: 19.390000sec

#                                    user     system      total        real
# Scan (regexp)                  5.000000   0.010000   5.010000 (  5.071590)
# Scan (string)                  6.420000   0.020000   6.440000 (  6.509148)
# Include                        0.870000   0.000000   0.870000 (  0.884166)
# =~                             1.310000   0.000000   1.310000 (  1.321260)
#
# Scan (regexp) (not findable)   1.610000   0.000000   1.610000 (  1.618463)
# Scan (string) (not findable)   2.780000   0.000000   2.780000 (  2.789644)
# Include (not findable)         0.830000   0.000000   0.830000 (  0.831013)
# =~ (not findable)              0.980000   0.010000   0.990000 (  0.985075)