Iterate over loop accessing two elements if they exist

Question

Well, I haven't found a clean solution to write this code easily in Ruby:

# Java style version:
array.each do |i, el|
  if i < array.length - 1
     process(array[i], array[i+1])
  end
end

# Would be nice if I could do something like this:
array.each do |i, el, next|
  process(el, next)
end

don't use `next` as variable, it's a flow control statement. — tokland, Aug 07 '13 at 19:35
Thanks for the point @tokland, it was just a matter of example. — Augustin Riedinger, Aug 07 '13 at 22:07

Platinum Azure · Accepted Answer · 2013-08-07T19:42:15.243

8

You can use each_cons:

array.each_cons(2) do |a, b|
  process(a, b)
end

edited Aug 07 '13 at 19:42

answered Aug 07 '13 at 19:25

Platinum Azure

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Good ol' `each_cons` saves the day again! – the Tin Man Aug 07 '13 at 20:05

Arup Rakshit · Answer 2 · 2013-08-07T20:01:29.320

2

ar = [1,2,3,4]
(ar.size - 1).times {|i| process ar[i],ar[i+1]}

edited Aug 07 '13 at 20:01

answered Aug 07 '13 at 19:27

Arup Rakshit

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Iterate over loop accessing two elements if they exist

2 Answers2