Iterate pairwise through a ruby array [duplicate]

You are looking for each_cons:

(1..6).each_cons(2) { |a, b| p a: a, b: b }
# {:a=>1, :b=>2}
# {:a=>2, :b=>3}
# {:a=>3, :b=>4}
# {:a=>4, :b=>5}
# {:a=>5, :b=>6}