elixir map
Elixir Map
In Elixir, a map is a data structure that stores key-value pairs. It is similar to a dictionary or an associative array in other programming languages. Maps are defined using the %{}
syntax, where keys and values are separated by =>
. Here's an example of a map in Elixir:
map = %{name: "John", age: 30, city: "New York"}
To access the value associated with a specific key in a map, you can use the dot notation or the square bracket notation. Here are examples of both:
name = map.name
age = map[:age]
To update a value in a map, you can use the Map.put/3
function. It takes the map, the key, and the new value as arguments and returns a new map with the updated value. Here's an example:
new_map = Map.put(map, :age, 31)
To add a new key-value pair to a map, you can use the Map.put_new/3
function. It works similarly to Map.put/3
, but it only adds the key-value pair if the key doesn't already exist in the map. Here's an example:
new_map = Map.put_new(map, :city, "Los Angeles")
To remove a key-value pair from a map, you can use the Map.delete/2
function. It takes the map and the key as arguments and returns a new map without the specified key-value pair. Here's an example:
new_map = Map.delete(map, :age)
It's important to note that maps in Elixir are immutable, which means that any operation on a map will return a new map without modifying the original one.