The ``loop.length``, ``loop.revindex``, ``loop.revindex0``, and
``loop.last`` variables are only available for PHP arrays, or objects that
- implement the ``Countable`` interface.
+ implement the ``Countable`` interface. They are also not available when
+ looping with a condition.
.. versionadded:: 1.2
The ``if`` modifier support has been added in Twig 1.2.
</ul>
The advantage is that the special loop variable will count correctly thus not
-counting the users not iterated over.
+counting the users not iterated over. Keep in mind that properties like
+``loop.last`` will not be defined when using loop conditions.
.. note::