Ruby: Enumerable#partition

If you want to sort values from an enumerable into two arrays based on whether they match a certain criteria or not, Enumerable#partition Show archive.org snapshot can come in handy.

# Enumerable#partition returns two arrays, 
# the first containing the elements of enum 
# for which the block evaluates to true, 
# the second containing the rest.

(1..6).partition { |v| n.even? }  #=> [[2, 4, 6], [1, 3, 5]]

Works well with destructuring assignment, too.

even, odd = (1..6).partition { |n| n.even? }
even #=> [2, 4, 6]
odd  #=> [1, 3, 5]