Benchmarking in ruby

require 'benchmark'

def m1
  %w{perro leon armario cazador escopeta arco}.inject{|memo, word| memo.length >  word.length ? memo : word}
end

def m2
  %w{perro leon armario cazador escopeta arco}.max{|a,b| a.length <=> b.length}
end


def m3
  %w{perro leon armario cazador escopeta arco}.max_by{|word| word.length}
end

n = 1000000
Benchmark.bm(7) do |x|
  x.report("inject:") { n.times {m1} }
  x.report("max:") { n.times {m2} }
  x.report("max_by:") { n.times {m3} }
end


Results:
              user     system      total        real
inject:   2.170000   0.000000   2.170000 (  2.356248)
max:      2.210000   0.020000   2.230000 (  2.429657)
max_by:   2.100000   0.030000   2.130000 (  2.316363)

require 'benchmark'
n=1000
Benchmark.bm(7) do |x|
  x.report("map: ") {n.times { User.all.includes(:contracted_plans).map{|u| [u] if (u.current_contracted_plan.nil? || u.current_contracted_plan.is_cancelled?) }.compact.flatten }}
  x.report("ids: ") {n.times { User.all.where.not(id: ContractedPlan.all.pluck(:user_id)) }}
end