Array element additions in ruby

Question

I have this array:

a1 = [1,2,3,4]

I want to generate this array from a1:

a2 = [3, 5, 7]

The formula is [a1[0] + a1[1], a1[1] + a1[2], ...].

What is the Ruby way to do this?

Arup Rakshit · Accepted Answer · 2013-06-29 21:09:11Z

14

Yes, you can do this as below:

a1 = [1,2,3,4]
a2 = a1.each_cons(2).map{ |a| a.inject(:+) } #=> [3, 5, 7]

answered May 19, 2013 at 17:28

Arup Rakshit

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1 Comment

The second line could also be a2 = a1.each_cons(2).map{ |a,b| a + b } which I find a bit easier to read.