What's the efficient way to multiply two arrays and get sum of multiplied values in Ruby?

Question

What\'s the efficient way to multiply two arrays and get sum of multiply values in Ruby? I have two arrays in Ruby:

array_A = [1, 2, 1, 4, 5, 3, 2, 6, 5, 8, 9]
a         


        

Answer 1

Since speed is our primary criterion, I'm going to submit this method as it's fastest according to Peter's benchmarks.

sum, i, size = 0, 0, a1.size
while i < size
  sum += a1[i] * a2[i]
  i += 1
end
sum