Fetch vs []

test.rb

require "benchmark/ips"

hash = Hash.new

Benchmark.ips do |x|
  x.report("fetch") { x = hash.fetch(:foo, "bar") }
  x.report("fetch block") { x = hash.fetch(:foo) { "bar" } }
  x.report("[]") { x = hash[:foo] || "bar" }
end

zresult

[~] ruby test.rb
Calculating -------------------------------------
               fetch   112.887k i/100ms
         fetch block   100.862k i/100ms
                  []   117.423k i/100ms
-------------------------------------------------
               fetch      4.399M (± 5.7%) i/s -     22.013M
         fetch block      3.259M (± 5.8%) i/s -     16.239M
                  []      5.079M (± 6.0%) i/s -     25.363M