Tests are used to perform logical operations within templated expressions such as checking if a variable is defined or if a variable is empty.
Each section below represents a built-in test.
defined
The defined test checks if a variable is defined.
twig
{% if missing is not defined %}
...
{% endif %}
empty
The empty test checks if a variable is empty. A variable is empty if it is null, an empty string, an empty collection, or an empty map.
twig
{% if user.email is empty %}
...
{% endif %}
even
The even test checks if an integer is even.
twig
{% if 2 is even %}
...
{% endif %}
iterable
The iterable test checks if a variable implements java.lang.Iterable.
twig
{% if users is iterable %}
{% for user in users %}
...
{% endfor %}
{% endif %}
json
The json test checks if a variable is valid json string
twig
{% if '{"test": 1}' is json %}
...
{% endif %}
map
The map test checks if a variable is an instance of a map.
twig
{% if {"apple":"red", "banana":"yellow"} is map %}
...
{% endif %}
null
The null test checks if a variable is null.
twig
{% if user.email is null %}
...
{% endif %}
odd
The odd test checks if an integer is odd.
twig
{% if 3 is odd %}
...
{% endif %}