inject method in ruby(reference : Eloquent ruby)

rb

class Document
  def average_word_length
    total = 0.0
    words.each { |word| total += word.size }
    total / word_count
  end
end

#This is the kind of problem that the inject method is tailor-made to solve. Like each , inject takes a block and calls the 
#block with each element of the collection. Unlike each , inject passes in two arguments to the block: Along with each 
#element, you get the current result—the current sum if you are adding up all of the word lengths. Each time inject calls 
#the block, it replaces the current result with the return value of the previous call to the block. When inject runs out of 
#elements, it returns the result as its return value. Here, for example, is our average_word_length method, reworked to use


#inject :
def average_word_length
  total = words.inject(0.0){ |result, word| word.size + result}
  total / word_count
end