nums = [1, 2, 3, 4, 5]

Enum.map(nums, fn n ->
   n * 2
end)
# [2, 4, 6, 8, 10]

Enum.filter(nums, fn n ->
   rem(n, 2) == 1
end)
# [1, 3, 5]

Enum.filter(nums, fn n ->
   rem(n, 2) != 1
end)
# [2, 4]

Enum.reduce(nums, fn a, b ->
   a + b
end)
# 15

Enum.each(nums, fn n ->
   IO.puts n * 100
end)
# 100
# 200
# 300
# 400
# 500
# :ok