topic Re: How to change a variable outside of a for loop? Scoping Issues in CMS Development

How to change a variable outside of a for loop? Scoping Issues

tjoyce — Wed, 10 Oct 2018 20:23:52 GMT

This question is extremely common; How do I use a counter in a variable that was created outside of a for loop. @Jsum did a good job answering that question here. I just wanted to expand on it and make this post more "searchable" by users trying to accomplish the same thing.

{# create the counter #}
{% set counter = {'value': 1} %}

{# create a macro that will change the counter, when called #}
{% macro incrementDecrementCounter(valuechange) %}
  {% set changingCounter = counter.update({'value': counter.value + valuechange}) %}
{% endmacro %}

{# the for...loop #}
{% for n in range(10) %}
  {% if n % 3 == 0 %}
    
    {# call the macro to update the counter #}
    {{incrementDecrementCounter(-1)}}
  {% else %}

    {# call the macro to update the counter #}
    {{incrementDecrementCounter(1)}}
  {% endif %}
  <p>The loop index is: {{n}}, while the counter is: {{counter.value}}</p>
{% endfor %}

@Anton, @dennisedson, @Stephanie-OG

Re: How to change a variable outside of a for loop? Scoping Issues

jennysowyrda — Thu, 11 Oct 2018 21:22:57 GMT

Thanks for sharing @tjoyce!

Re: How to change a variable outside of a for loop? Scoping Issues

matt_scott — Fri, 16 Aug 2019 15:35:23 GMT

I didn't think of using a macro, that's a nice solution!

I found a hacky way to do something similar but different
This was some code I used to build a dictionary:
The ‘.append’ function actually appends to the global dictionary ‘vars’, the variable inside the set is irrelevant but is needed for the hubl to run

{% set vars = [] %}
{% for item in group %}
    {% set thisVariableDoesntDoAnything = vars.append(item.variable) %}
{% endfor %}

Re: How to change a variable outside of a for loop? Scoping Issues

matt_scott — Mon, 21 Dec 2020 09:32:44 GMT

Since writting the above I found the "do" function and hubspot have now added the "do" function to the docs so the code doesn't seem so hacky

{% set vars = [] %} {% for item in group %} {% do vars.append(item.variable) %} {% endfor %}

Re: How to change a variable outside of a for loop? Scoping Issues

mIIwaukee — Tue, 05 Oct 2021 18:40:08 GMT

Thanks everyone, here's a non-array approach.

{% set thisClient = {'name': 'none' } %} {% for client in dynamic_page_hubdb_row.client %} {% do thisClient.update({'name': client.name }) %} {% endfor %} {{thisClient.name}}

Re: How to change a variable outside of a for loop? Scoping Issues

gotohubspot — Fri, 20 Sep 2024 08:47:37 GMT

If you will use an array ( SizeLimitingPyList: [] ) rather than object ( SizeLimitingPyMap: {} ) it would be accessible in for loop.

Re: How to change a variable outside of a for loop? Scoping Issues

darveesh — Fri, 29 Aug 2025 00:37:29 GMT

I spent a whole day pulling my hair out until I came across this article. Maybe there are good reason to not allow outer variable to be set inside the for loop with a good old set statement. But it's super counter intuitive (based on perhaps 99% of other languages out there). Big lame factor here imho.

Re: How to change a variable outside of a for loop? Scoping Issues

BérangèreL — Fri, 29 Aug 2025 06:46:17 GMT

Hi @darveesh and thank you for sharing your experience and feedback with the HubSpot Community!

I completely understand how frustrating it can be to run into unexpected scoping behavior, especially when it feels counter to conventions in other languages.

I'd recommend submitting this via the HubSpot Developer Feedback Form, then the right team can have their eyes on it.

We’re always working to improve, and your feedback about the developer experience is important.

Thank you again for being part of the HubSpot Community!

Have a great weekend!
Bérangère