reduce_vs_without.rb

a = [1,2]

Benchmark.ips do |x|
  x.report("reduce") { a.reduce(:*) }
  x.report("other") { a[0] * a[1] }
  x.compare!
end

Calculating -------------------------------------
              reduce    56.411k i/100ms
               other    78.330k i/100ms
-------------------------------------------------
              reduce      1.644M (± 8.7%) i/s -      8.180M
               other      4.696M (±14.1%) i/s -     22.951M

Comparison:
               other:  4696074.3 i/s
              reduce:  1643904.7 i/s - 2.86x slower