default Twig Filter

The default filter returns the passed default value if the variable is undefined or empty, otherwise, it returns the variable value.

The default value value will be used if the passed value is:

undefined
an empty string
an empty array
an empty object
false
null

{{ variable|default('My Default Value') }}
{{ item.name|default('Default item name') }}
{{ post.image.tag|default('No image set') }}
{{ product['manufacturer']|default('Nobody manufactures this product') }}
{{ ''|default('The passed variable is empty') }}

It is a good idea to use the default filter if you are using a variable in a place where it must have a value.

{% do redirect(urlToGoTo|default('/default-page')) %}

See "Set a default value if the attribute doesn't have a value" on the Twig HTML Objects page for more information.

If you need to support a boolean false value, then use the null-coalescing ?? operator.

{% set var = false %}

{# Instead of this #}
{% set value = var|default(true) %}

{# Do this #}
{% set value = var ?? true %}