How to sum array of numbers in Ruby?
Try this:
array.inject(0){|sum,x| sum + x }
See Ruby's Enumerable Documentation
(note: the 0
base case is needed so that 0
will be returned on an empty array instead of nil
)
array.reduce(0, :+)
While equivalent to array.inject(0, :+)
, the term reduce is entering a more common vernacular with the rise of MapReduce programming models.
inject, reduce, fold, accumulate, and compress are all synonymous as a class of folding functions. I find consistency across your code base most important, but since various communities tend to prefer one word over another, it’s nonetheless useful to know the alternatives.
To emphasize the map-reduce verbiage, here’s a version that is a little bit more forgiving on what ends up in that array.
array.map(&:to_i).reduce(0, :+)
Some additional relevant reading: