How to sum the integer inside array of arrays?

Question

a = [[5, 6], [6, 5], [7, 4], [1, 0, 0], [9, 9], [6, 8], [8, 6], [1, 8, 0], [9, 0]]

How can I sum the integers inside the inner array and return an array of sum of the inner array?

I need it to return [(5+6), (6+5), (7+4), (1+0+0), ...], thus [11, 11, 11, 1, 18, 14, 14, 9, 9]

When asking, we expect to see evidence of your effort toward solving the problem. It looks like you're asking us to write the code for you, which is not what we do. Please read "How to Ask", including the linked pages, and "minimal reproducible example". — the Tin Man
– the Tin Man, Commented Jul 12, 2016 at 0:03
@theTinMan definitely! I did all my scratch work on repl.it for almost a good hour, but later I closed the page so I could not show the codes I have tried. I will do so next time. Thanks for the heads up! — Iggy
– Iggy, Commented Jul 12, 2016 at 0:19

sawa · Accepted Answer · 2016-07-11 17:06:24Z

5

a.map{|a| a.inject(:+)}
# => [11, 11, 11, 1, 18, 14, 14, 9, 9]

answered Jul 11, 2016 at 17:06

sawa

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1 Comment

You're a ninja. Beat me by 18 seconds because my response was too short

lwassink · Accepted Answer · 2016-07-11 17:06:42Z

5

Try

sum_arry = a.map { |sub_arry| sub_arry.inject(&:+) }

Then sum_arry should be the array you want.

answered Jul 11, 2016 at 17:06

lwassink

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Richard Hamilton · Accepted Answer · 2016-07-11 17:08:17Z

4

Use map + reduce

a.map { |a| a.reduce(:+) }

answered Jul 11, 2016 at 17:06

Richard Hamilton

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If all one can usefully say as an answer to a question is 29 characters or less, is the question really worth answering?

I personally thought it was a pretty good question. Answers are good if they can be less than 30 chars. Just my opinion

Any other interesting ways to do this?