List.first

You're seeing just the function first, go back to List module for more information.

first(list, default \\ nil)

first([], any()) :: any()

first([elem, ...], any()) :: elem when elem: var

Returns the first element in list or default if list is empty.

first/2 has been introduced in Elixir v1.12.0, while first/1 has been available since v1.0.0.

iex> List.first([])
nil

iex> List.first([], 1)
1

iex> List.first([1])
1

iex> List.first([1, 2, 3])
1