Programming Elixir ≥ 1.6

Maps

Maps are the go-to key/value data structure in Elixir. They have good performance at all sizes.

Let’s play with the Map API:^[16]

iex> map = %{ name: "Dave", likes: "Programming", where: "Dallas" }
%{likes: "Programming", name: "Dave", where: "Dallas"}
iex> Map.keys map
[:likes, :name, :where]
iex> Map.values map
["Programming", "Dave", "Dallas"]
iex> map[:name]
"Dave"
iex> map.name
"Dave"
iex> map1 = Map.drop map, [:where, :likes]
%{name: "Dave"}
iex> map2 = Map.put map, :also_likes, "Ruby"
%{also_likes: "Ruby", likes: "Programming", name: "Dave", where: "Dallas"}
iex> Map.keys map2
[:also_likes, :likes, :name, :where]
iex> Map.has_key? map1, :where
false
iex> { value, ...