Representation

Documentation

An atom is a constant which name is its value. Every atom starts with colon and ends with word or operator known for Elixir. Things to remember when creating an atom:

• must be a sequence of UTF-8 letters,

• might consist of digits,

• might include the underscore,

• might include @,

• might end with ? or !,

• can be created with any string when enclosed within quotes.

Example of atoms:

:hello, :"hello world", :+, :===, :exists?

Two atoms with the same naming always represent the same value.

iex> :hello == :hello
true
iex> :hello == :"hello"
true
iex> :hello == :"hello world"
false

You can check if given value is atom with is_atom/1 function:

iex> is_atom :hello
true
iex> is_atom "hello"
false
iex> is_atom :"hello"
true

You'll be using atoms very often to tag values.