array = [1,2,3,4,5] new_array = [] front_index = 0 back_index = array.length-1 while front_index <= back_index new_array << array[front_index] front_index += 1 if front_index <= back_index new_array << array[back_index] back_index -= 1 end end p new_array # => [1, 5, 2, 4, 3]