``merge``
=========
The ``merge`` filter merges an array with another array:
.. code-block:: jinja
{% set values = [1, 2] %}
{% set values = values|merge(['apple', 'orange']) %}
{# values now contains [1, 2, 'apple', 'orange'] #}
New values are added at the end of the existing ones.
The ``merge`` filter also works on hashes:
.. code-block:: jinja
{% set items = { 'apple': 'fruit', 'orange': 'fruit', 'peugeot': 'unknown' } %}
{% set items = items|merge({ 'peugeot': 'car', 'renault': 'car' }) %}
{# items now contains { 'apple': 'fruit', 'orange': 'fruit', 'peugeot': 'car', 'renault': 'car' } #}
For hashes, the merging process occurs on the keys: if the key does not
already exist, it is added but if the key already exists, its value is
overridden.
.. tip::
If you want to ensure that some values are defined in an array (by given
default values), reverse the two elements in the call:
.. code-block:: jinja
{% set items = { 'apple': 'fruit', 'orange': 'fruit' } %}
{% set items = { 'apple': 'unknown' }|merge(items) %}
{# items now contains { 'apple': 'fruit', 'orange': 'fruit' } #}
.. note::
Internally, Twig uses the PHP `array_merge`_ function. It supports
Traversable objects by transforming those to arrays.
.. _`array_merge`: http://php.net/array_merge
|