From: daz <dooby@...10.karoo.co.uk>
Date: 2005-07-08T18:00:47+09:00
Subject: Re: accessing index inside map


Pe�a, Botp wrote:

> [...] i cannot find something like array#each_with_index...

David Black was once President of Citizens for MWI, Inc.
(google "map with index" MWI).

Welcome!


You can add your own, of course.

module Enumerable
  def map_with_index!
    each_with_index do |e, ix|
      self[ix] = yield e, ix
    end
    self
  end
end

arr = (1..6).to_a
arr.map_with_index! do |e, ix|
  [2, 5].include?(ix) ? e : e*2
end

p arr
#=> [2, 4, 3, 8, 10, 6]


daz