How to count variable +1 in Liquid

Question

I am completely stumped by how to count plus one towards a variable assigned via {% assign var = 0 %}. It should be the most simple task. Here's what I've tried so far:

{% assign amount = 0 %}
{% for variant in product.variants %}
    {% assign amount = amount + 1 %}
{% endfor %}

Amount: {{ amount }}

The result is always 0. Maybe I'm overlooking something obvious. Maybe there is a better way altogether. All I want to archive is getting the number of iterations that are run.

Answer 1

As {{ increment amount }} will output your variable value and does not affect a variable defined by {% assign %}, I suggest you to use {% capture %}:

{% assign amount = 0 %}
{% for variant in product.variants %}
    {% capture amount %}{{ amount | plus:1 }}{% endcapture %}
{% endfor %}

Amount: {{ amount }}

I agree this is verbose, but it's AFAIK the only working solution.