Added small section about default values

j92 · j92 · commit a0320fd5d973 · 2019-07-13T14:31:26.000+02:00
diff --git a/components/dotenv.rst b/components/dotenv.rst
@@ -141,6 +141,13 @@ Use environment variables in values by prefixing variables with ``$``:
     DB_USER=root
     DB_PASS=${DB_USER}pass # Include the user as a password prefix
 
+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
