# Intro to variables

### What are variables?

Variables are pieces of code that Hubble replaces with real data when a customer views your content. For example, instead of saying "Hello customer", you can use a variable to say "Hello Jane".

### Why use them?

Personalization is key to engaging customers. Variables allow you to:

* Greet customers by name
* Display specific account details
* Show relevant dates or information

### How they work inside Hubble

Hubble's variables follow Shopify Liquid’s nomenclature and style so that they feel familiar to merchants who are used to Shopify.

#### Liquid-inspired syntax

Variables are wrapped in double curly braces: `{{ }}`.

**Example:** `{{ customer.first_name }}`

{% hint style="warning" %}
**This is NOT Shopify Liquid.**

Many Liquid variables exist in Shopify, but Hubble only supports the variables that appear in our **variable modal picker**.

Attempting to use a Liquid-like variable not provided by Hubble will not work.
{% endhint %}

### Limitations

The most important rule to remember is: **If it's not in the modal picker, it's not supported.**

Hubble uses a specific engine to render these variables, so standard Liquid logic (like `{% if %}` tags or complex loops) or unsupported variable names will not function as expected.

### Examples

Here are a few basic ways to use variables:

**Simple variable:**

```liquid
{{ customer.first_name }}
```

**Variable with a fallback (default value):**

```liquid
{{ customer.name | default: 'dear customer!' }}
```

### Common variables

Here are some of the most commonly used variables available in Hubble:

| Variable              | Description                        |
| --------------------- | ---------------------------------- |
| `customer.first_name` | The customer's first name.         |
| `customer.last_name`  | The customer's last name.          |
| `customer.email`      | The email address of the customer. |