Matthias Andreas Benkard | 12a5735 | 2021-12-28 18:02:04 +0100 | [diff] [blame^] | 1 | ``reverse`` |
| 2 | =========== |
| 3 | |
| 4 | The ``reverse`` filter reverses a sequence, a mapping, or a string: |
| 5 | |
| 6 | .. code-block:: twig |
| 7 | |
| 8 | {% for user in users|reverse %} |
| 9 | ... |
| 10 | {% endfor %} |
| 11 | |
| 12 | {{ '1234'|reverse }} |
| 13 | |
| 14 | {# outputs 4321 #} |
| 15 | |
| 16 | .. tip:: |
| 17 | |
| 18 | For sequences and mappings, numeric keys are not preserved. To reverse |
| 19 | them as well, pass ``true`` as an argument to the ``reverse`` filter: |
| 20 | |
| 21 | .. code-block:: twig |
| 22 | |
| 23 | {% for key, value in {1: "a", 2: "b", 3: "c"}|reverse %} |
| 24 | {{ key }}: {{ value }} |
| 25 | {%- endfor %} |
| 26 | |
| 27 | {# output: 0: c 1: b 2: a #} |
| 28 | |
| 29 | {% for key, value in {1: "a", 2: "b", 3: "c"}|reverse(true) %} |
| 30 | {{ key }}: {{ value }} |
| 31 | {%- endfor %} |
| 32 | |
| 33 | {# output: 3: c 2: b 1: a #} |
| 34 | |
| 35 | .. note:: |
| 36 | |
| 37 | It also works with objects implementing the `Traversable`_ interface. |
| 38 | |
| 39 | Arguments |
| 40 | --------- |
| 41 | |
| 42 | * ``preserve_keys``: Preserve keys when reversing a mapping or a sequence. |
| 43 | |
| 44 | .. _`Traversable`: https://secure.php.net/Traversable |