丹通枚举的地图

丹枚举的地图

iex> Enum.map(1..3, fn x -> x * 2 end)
[2, 4, 6]

iex> map = %{"a" => 1, "b" => 2}
iex> Enum.map(map, fn {k, v} -> {k, v * 2} end)
[{"a", 2}, {"b", 4}]