How can I unset a variable in liquid?

Question

How can I unset a variable in liquid, that has been created via an earlier {% assign ... %} statement?

Answer 1

In Liquid, you won't find a command like "unset" that does what you want directly.

However, you can make a variable empty and and effectively non-existent using the value nil:

{% assign foo = nil %}

In a boolean expression, a variable with the value nil is considered false.

In the example below Liquid will print nothing:

{% assign foo = nil %}
{% if foo %}
  <p>I'm a paragraph.</p>
{% endif %}

You can find more info here.