default

Sets a default value for any variable with no assigned value. default will show its value if the input is nil, false, or empty.

In this example, product_price is not defined, so the default value is used.

输入

{{ product_price | default: 2.99 }}

输出

2.99

In this example, product_price is defined, so the default value is not used.

输入

{% assign product_price = 4.99 %}
{{ product_price | default: 2.99 }}

输出

4.99

In this example, product_price is empty, so the default value is used.

输入

{% assign product_price = "" %}
{{ product_price | default: 2.99 }}

输出

2.99

Allowing false Permalink

To allow variables to return false instead of the default value, you can use the allow_false parameter.

输入

{% assign display_price = false %}
{{ display_price | default: true, allow_false: true }}

输出

false