is_undefined

Tests if a value is undefined.

Checks if the value is empty and outputs a boolean true or false. This is useful in combination with the if tag.

For example:

{% if value[1]|is_undefined %}The first elemeent of value was undefined{% endif %}

If the value is [] then the output is The first elemeent of value was undefined.

Edit on GitHub

is_defined Variables make_value

Referred by

Filters

Filters transform template variables before they are rendered.