http://stackoverflow.com/q/10140983/1232000

bench.rb

require 'benchmark'

Benchmark.bmbm(10) do |x|
  x.report("noregexp") {
    "content-management-systems".split("-").map(&:capitalize).join(" ").
    split(" ").map(&:downcase).join("-")
  }

  x.report("rgexp") {
    "content-management-systems".
    gsub(/(\w+)(-)?/) { ($2 ? $1 + " " : $1).capitalize! }.
    gsub(/(\w+)(\s)?/) { ($2 ? $1 + "-" : $1).downcase! }
  }
end

__END__

Rehearsal ----------------------------------------------
noregexp     0.000000   0.000000   0.000000 (  0.000032)
rgexp        0.000000   0.000000   0.000000 (  0.000035)
------------------------------------- total: 0.000000sec

                 user     system      total        real
noregexp     0.000000   0.000000   0.000000 (  0.000051)
rgexp        0.000000   0.000000   0.000000 (  0.000058)