Exercism.io Hamming

hamming_original.rb

class Hamming
  def self.compute(first_gene, second_gene)
    length = first_gene.length < second_gene.length ? first_gene.length : second_gene.length
    score = 0
    (0..(length - 1)).each do |index|
      score += 1 unless first_gene[index] == second_gene[index]
    end
    score
  end
end

hamming_revised.rb

class Hamming
  def self.compute(first, second)
    length = [first.size, second.size].min
    (0...length).inject(0) do |sum, index|
      first[index] == second[index] ? sum : sum += 1
    end
  end
end