Is there a simple way to select the second to last item in Ruby?

Question

Is there a simple way to select the second to last item in Ruby? Something similar to like the nth-child selector in css?

Here is my code:

def pic2
    @pic2 ||= begin
      result = card.attachments&.last&.url # I need this to be changed to select the second to last attachment instead of the last
      if result
        logger_card("Pic found on trello card (#{result})")
        result
      else
        logger_card('No Trello Picture')
        nil
      end
    end
  end

I need that third line changed to select the second to last attachment instead of the last

score 2 · Accepted Answer · edited Sep 01 '21 at 12:04

2

result = card.attachments[-2].url

Something like that?

edited Sep 01 '21 at 12:04

Sergio Tulentsev

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answered Aug 31 '21 at 23:28

thomas305

82
7

You initially had the [-2] in the wrong place, so I moved it in your answer. Just an FYI. Thanks for the answer! – McKay Whiting Aug 31 '21 at 23:39

score 1 · Answer 2 · answered Sep 01 '21 at 12:46

If you use Rails, you can use Array#second_to_last method:

card.attachments.second_to_last

It is just ActiveSupport syntax sugar for [-2] that Sergio proposed

You can also use this method in pure Ruby. Just include this part of library in your code:

require 'active_support/core_ext/array/access'

score -2 · Answer 3 · answered Aug 31 '21 at 23:37

-2

One thing that also works that I was planning on using before @WesleyBond posted was the following:

card.attachments&.reverse[1].url

answered Aug 31 '21 at 23:37

McKay Whiting

152
11

Is there a simple way to select the second to last item in Ruby?

3 Answers3