charmaps.rb

#                        user     system      total        real
# case               0.050000   0.000000   0.050000 (  0.059868)
# if                 0.090000   0.000000   0.090000 (  0.091604)
# hash               0.070000   0.000000   0.070000 (  0.081646)
# bad hash           0.690000   0.020000   0.710000 (  0.709891)


require 'benchmark'

iterations = 1_000_000
HASH = { 1 => 1, 2 => 2, 3 => 3, 4 => 4 }
Benchmark.bm(16) do |bm|
  bm.report 'case' do
    iterations.times do |i|
      case i
      when 1
        @x = 1
      when 2
        @x = 2
      when 3
        @x = 3
      when 4
        @x = 4
      end
    end
  end

  bm.report 'if' do
    iterations.times do |i|
      if i == 1
        @x = 1
      elsif i == 2
        @x = 2
      elsif i == 3
        @x = 3
      elsif i == 4
        @x = 4
      end
    end
  end

  bm.report 'hash' do
    iterations.times do |i|
      if HASH[i]
        @x = HASH[i]
      end
    end
  end

  bm.report 'bad hash' do
    iterations.times do |i|
      hash = { 1 => 1, 2 => 2, 3 => 3, 4 => 4 }
      if hash[i]
        @x = hash[i]
      end
    end
  end
end