Erlang Tuples (Tuple)Erlang Atoms (Atom)

Erlang Maps (Map)

Mapping is a data structure with a variable number of keys-Composite data type associated with values. Each key-value association in the mapping is called an association pair. The key and value parts of the pair are called elements. The number of association pairs is called the size of the mapping.

The following program demonstrates an example of how to use the Map data type.

Here we define a Map M1It has2a map.map_size is a built-in function defined in Erlang, which can be used to determine the size of a map.

Online Example

Example

-module(helloworld).　
-export([start/　
start()　->　
　　　M1　=  #{name=>john,age=>25},　
　　　io:fwrite("~w",[map_size(M1)]).

The output of the above program is as follows.

Some other methods applicable to maps are as follows.

Serial Number	Methods and Descriptions
1	from_list This method is used to generate a map from a list.
2	find This method is used to find if a specific key exists in the map.
3	get This method is used to get the value of a specific key in the map.
4	is_key This method is used to determine if a specific key is defined as a key in the map.
5	keys This method is used to return all keys from the map.
6	merge This method is used to merge2A map.
7	put This method is used to add a key-value pair to the map.
8	values This method is used to return all values from the map.
9	remove This method is used to remove the key-value from the map.

Erlang Tutorial

Erlang Maps (Map)

Online Example