Add example for Access.get_and_update/3 (#9261)

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/elixir/lib/access.ex b/lib/elixir/lib/access.ex
index e654d5286..bb0d1da0e 100644
--- a/lib/elixir/lib/access.ex
+++ b/lib/elixir/lib/access.ex
@@ -329,6 +329,14 @@ defmodule Access do
 
   The returned value is a two-element tuple with the "get" value returned by
   `fun` and a new container with the updated value under `key`.
+
+  ## Examples
+
+      iex> Access.get_and_update([a: 1], :a, fn current_value ->
+      ...>   {current_value, current_value + 1}
+      ...> end)
+      {1, [a: 2]}
+
   """
   @spec get_and_update(data, key, (value -> {get_value, value} | :pop)) :: {get_value, data}
         when get_value: var, data: container