> For the complete documentation index, see [llms.txt](https://learn.mechanic.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://learn.mechanic.dev/platform/liquid/tags/assign.md).

# assign

The **assign** tag is a native feature of Liquid. In Mechanic-flavored Liquid, the assign tag is extended to support assigning within [**arrays**](/platform/liquid/basics/types.md#array) and [**hashes**](/platform/liquid/basics/types.md#hash).

Assignment into arrays and hashes is always by value, never by reference.

{% hint style="info" %}
"Assignment by value" means that the result of the assignment will never dynamically change.

```
{% assign foo = "bar" %}
{% assign x = array %}
{% assign x["foo"] = foo %}

{% assign foo = "qux" %}
```

At the end of this example, `x.foo` still contains `"bar"`, even though the value of the original `foo` variable has changed.
{% endhint %}

## Assigning into arrays

Arrays support assignment by index, using integer lookups.

{% tabs %}
{% tab title="Code" %}

```liquid
{% assign x = array %}
{% assign x[0] = "one" %}
{% assign x[x.size] = "two" %}

{% assign the_third_zero_based_index = 2 %}
{% assign x[the_third_zero_based_index] = "three" %}

{{ x | json }}
```

{% endtab %}

{% tab title="Output" %}

```liquid
["one","two","three"]
```

{% endtab %}
{% endtabs %}

## Assigning into hashes

Hashes support assignment by key, using string lookups.

{% tabs %}
{% tab title="Code" %}

```liquid
{% assign x = hash %}
{% assign x["one"] = 1 %}
{% assign x["two"] = 2 %}

{% assign three = "three" %}
{% assign x[three] = 3 %}

{{ x | json }}
```

{% endtab %}

{% tab title="Output" %}

```liquid
{"one":1,"two":2,"three":3}
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://learn.mechanic.dev/platform/liquid/tags/assign.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.