Erlang - Atoms


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An atom is a literal, a constant with name. An atom is to be enclosed in single quotes (') if it does not begin with a lower-case letter or if it contains other characters than alphanumeric characters, underscore (_), or @.

The following program is an example of how atoms can be used in Erlang. This program declares 3 atoms, atom1, atom_1 and ‘atom 1’ respectively. So you can see the different ways an atom can be declared.

Example

-module(helloworld). 
-export([start/0]). 

start() -> 
   io:fwrite(atom1), 
   io:fwrite("~n"), 
   io:fwrite(atom_1), 
   io:fwrite("~n"), 
   io:fwrite('atom 1'), 
   io:fwrite("~n").

The output of the above program would be follows −

Output

atom1
atom_1
atom 1

Let’s see some of the methods available in Erlang to work with atoms.

Sr.No. Methods and Description
1

is_atom

This method is used to determine if a term is indeed an atom.

2

atom_to_list

This method is used to convert an atom to a list.

3

list_to_atom

This method is used to convert a list item to an atom.

4

atom_to_binary

This method is used to convert an atom to a binary value.

5

binary_to_atom

This method is used to convert a binary value to an atom value.

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