benchmark_string_symbol_comparisons.rb

require "benchmark"

puts RUBY_DESCRIPTION

TIMES = 1_000_000

X_STRING = "x"
X_SYMBOL = :x

Benchmark.bm(7) do |x|
  a_string = "x"
  b_string = "x"
  a_symbol = :x
  b_symbol = :x

  # Strings

  x.report("String: variable == variable") do
    1.upto(TIMES) { a_string == b_string }
  end

  x.report("String: variable == string") do
    1.upto(TIMES) { a_string == "x" }
  end

  x.report("String: variable == constant") do
    1.upto(TIMES) { a_string == X_STRING }
  end

  # Symbols

  x.report("Symbol: variable == variable") do
    1.upto(TIMES) { a_symbol == b_symbol }
  end

  x.report("Symbol: variable == string") do
    1.upto(TIMES) { a_symbol == :x }
  end

  x.report("Symbol: variable == constant") do
    1.upto(TIMES) { a_symbol == X_SYMBOL }
  end
end

output

> ruby benchmark_string_symbol_comparisons.rb
ruby 1.9.3p327 (2012-11-10 revision 37606) [x86_64-darwin11.4.2]
              user     system      total        real
String: variable == variable  0.120000   0.000000   0.120000 (  0.116354)
String: variable == string  0.210000   0.000000   0.210000 (  0.217801)
String: variable == constant  0.110000   0.000000   0.110000 (  0.104247)
Symbol: variable == variable  0.160000   0.000000   0.160000 (  0.176373)
Symbol: variable == string  0.140000   0.000000   0.140000 (  0.135777)
Symbol: variable == constant  0.150000   0.000000   0.150000 (  0.154333)