feature #11956 Added small section about default values (j92)

OskarStark · OskarStark · commit 46ebb09bdca6 · 2019-08-06T09:53:36.000+02:00
This PR was merged into the 4.4 branch. Discussion ---------- Added small section about default values  Added a short description and a code sample of how to use default values when referenced variables are not set. The feature PR is symfony/symfony#31546. Commits ------- 1848e00 Added small section about default values
diff --git a/components/dotenv.rst b/components/dotenv.rst
@@ -149,6 +149,13 @@ Use environment variables in values by prefixing variables with ``$``:
     its value will depend on the ``DB_USER`` value defined in other files
     instead of the value defined in this file.
 
+Define a default value in case the environment variable is not set:
+
+ .. code-block:: terminal
+
+    DB_USER=
+    DB_PASS=${DB_USER:-root}pass # results in DB_PASS=rootpass
+
 Embed commands via ``$()`` (not supported on Windows):
 
 .. code-block:: terminal
