| ``merge`` |
| ========= |
| |
| The ``merge`` filter merges an array with another array: |
| |
| .. code-block:: twig |
| |
| {% 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:: twig |
| |
| {% 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:: twig |
| |
| {% 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`: https://secure.php.net/array_merge |