How to condense summable metrics to a unique identifier in a ruby table

Question

I\'m trying to condense summable metrics to a unique identifier in a ruby table.

I have the following table:

[[\"id1\", 123], [\"id2\", 234], [\"id1\", 3         


        

Answer 1

summable_metrics = [["id1", 123],["id2", 234], ["id1", 345]]

summable_metrics.group_by(&:first).map do |k, v|
  [k, v.map(&:last).reduce(:+)]
end

=> [["id1", 468], ["id2", 234]]