benchmark on the speed of constant and class variable.

constant_vs_class_variable.rb

require 'benchmark'

LOCALE_ARRAY = (1..1000000).to_a

class MyClass
  def self.vars
    @@vars
  end

  def self.vars=(args)
    @@vars = args if args.kind_of?(Array)
  end
end

MyClass.vars = (1..1000000).to_a


n = 10,000,000,000
Benchmark.bm do |x|
  x.report { LOCALE_ARRAY.include? 10240 }
  x.report { MyClass.vars.include? 10240 }

  x.report { LOCALE_ARRAY.find_index 10240 }
  x.report { MyClass.vars.find_index 10240 }
end

output.txt

╭─lucas@MacbookPro  ~ ‹ruby-2.1.1›
╰─$ ruby a.rb
       user     system      total        real
   0.000000   0.000000   0.000000 (  0.000500)
   0.000000   0.000000   0.000000 (  0.000472)
   0.000000   0.000000   0.000000 (  0.000079)
   0.000000   0.000000   0.000000 (  0.000074)
╭─lucas@MacbookPro  ~ ‹ruby-2.1.1›
╰─$ ruby a.rb
       user     system      total        real
   0.000000   0.000000   0.000000 (  0.000497)
   0.000000   0.000000   0.000000 (  0.000471)
   0.000000   0.000000   0.000000 (  0.000080)
   0.000000   0.000000   0.000000 (  0.000089)
╭─lucas@MacbookPro  ~ ‹ruby-2.1.1›
╰─$ ruby a.rb
       user     system      total        real
   0.000000   0.000000   0.000000 (  0.000501)
   0.000000   0.000000   0.000000 (  0.000473)
   0.000000   0.000000   0.000000 (  0.000081)
   0.000000   0.000000   0.000000 (  0.000074)