count_vs_size.rb

COUNT = 10_000_000

a = [1, 2, 3, 4]
h = { :x => 10, :y => 20, :z => 30 }

require 'benchmark'

Benchmark.bm(20) do |b|
  b.report("count arr:") { COUNT.times { a.count } }
  b.report("size arr:") { COUNT.times {  a.size } }
  b.report("count hash:") { COUNT.times {  h.count } }
  b.report("size hash:") { COUNT.times {  h.size } }
end



#                          user     system      total        real
#count arr:            1.320000   0.000000   1.320000 (  1.312148)
#size arr:             0.920000   0.000000   0.920000 (  0.920246)
#count hash:           6.380000   0.010000   6.390000 (  6.383174)
#size hash:            0.910000   0.000000   0.910000 (  0.909669)