ELIXIR

elixir enum map

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}]

elixir enum map

Enum.map([0, 1, 2, 3], fn(x) -> x - 1 end)
[-1, 0, 1, 2]