length

New in version 2.3: Support for the __toString() magic method has been added in Twig 2.3.

The length filter returns the number of items of a sequence or mapping, or the length of a string.

For objects that implement the Countable interface, length will use the return value of the count() method.

For objects that implement the __toString() magic method (and not Countable), it will return the length of the string provided by that method.

{% if users|length > 10 %}
    ...
{% endif %}