vendor/twig/twig/doc/filters/reverse.rst

   1 ``reverse``
   2 ===========
   3
   4 .. versionadded:: 1.6
   5     Support for strings has been added in Twig 1.6.
   6
   7 The ``reverse`` filter reverses a sequence, a mapping, or a string:
   8
   9 .. code-block:: jinja
  10
  11     {% for user in users|reverse %}
  12         ...
  13     {% endfor %}
  14
  15     {{ '1234'|reverse }}
  16
  17     {# outputs 4321 #}
  18
  19 .. tip::
  20
  21     For sequences and mappings, numeric keys are not preserved. To reverse
  22     them as well, pass ``true`` as an argument to the ``reverse`` filter:
  23
  24     .. code-block:: jinja
  25
  26         {% for key, value in {1: "a", 2: "b", 3: "c"}|reverse %}
  27             {{ key }}: {{ value }}
  28         {%- endfor %}
  29
  30         {# output: 0: c    1: b    2: a #}
  31
  32         {% for key, value in {1: "a", 2: "b", 3: "c"}|reverse(true) %}
  33             {{ key }}: {{ value }}
  34         {%- endfor %}
  35
  36         {# output: 3: c    2: b    1: a #}
  37
  38 .. note::
  39
  40     It also works with objects implementing the `Traversable`_ interface.
  41
  42 Arguments
  43 ---------
  44
  45  * ``preserve_keys``: Preserve keys when reversing a mapping or a sequence.
  46
  47 .. _`Traversable`: http://php.net/Traversable