`keys`

The keys filter returns the keys of a sequence or a mapping. It is useful when you want to iterate over the keys of a sequence or a mapping:

.. code-block:: twig

{% for key in ['a', 'b', 'c', 'd']|keys %}
    {{ key }}
{% endfor %}
{# outputs: 0 1 2 3 #}

{% for key in {a: 'a_value', b: 'b_value'}|keys %}
    {{ key }}
{% endfor %}
{# outputs: a b #}

.. note::

Internally, Twig uses the PHP `array_keys`_ function.

.. _array_keys: https://www.php.net/array_keys

``keys``

keys

`keys`