gistfile1.rb

require 'benchmark'

Benchmark.bm do |x|
  test = ["test", 1]
  x.report("   rescue") { 100000.times { test.collect{|x| x.strip! rescue nil} } }
  test = ["test", "test"]
  x.report("no rescue") { 100000.times { test.collect{|x| x.strip!} } }
  test = ["test", 1]
  x.report("  respond") { 100000.times { test.collect{|x| x.strip! if x.respond_to?(:strip!)} } }
end

      user     system      total        real
   rescue  1.590000   0.020000   1.610000 (  1.613629)
no rescue  0.070000   0.000000   0.070000 (  0.060558)
  respond  0.100000   0.000000   0.100000 (  0.180400)