| ``constant`` | |
| ============ | |
| ``constant`` returns the constant value for a given string: | |
| .. code-block:: twig | |
| {{ some_date|date(constant('DATE_W3C')) }} | |
| {{ constant('Namespace\\Classname::CONSTANT_NAME') }} | |
| You can read constants from object instances as well: | |
| .. code-block:: twig | |
| {{ constant('RSS', date) }} | |
| Use the ``defined`` test to check if a constant is defined: | |
| .. code-block:: twig | |
| {% if constant('SOME_CONST') is defined %} | |
| ... | |
| {% endif %} |