``if``
======

The ``if`` statement in Twig is comparable with the if statements of PHP. In
the simplest form you can use it to test if a variable is not empty:

.. code-block:: jinja

    {% if users %}
        <ul>
            {% for user in users %}
                <li>{{ user.username|e }}</li>
            {% endfor %}
        </ul>
    {% endif %}

.. note::

    If you want to test if the variable is defined, use ``if users is
    defined`` instead.

For multiple branches ``elseif`` and ``else`` can be used like in PHP. You can use
more complex ``expressions`` there too:

.. code-block:: jinja

    {% if kenny.sick %}
        Kenny is sick.
    {% elseif kenny.dead %}
        You killed Kenny!  You bastard!!!
    {% else %}
        Kenny looks okay --- so far
    {% endif %}
