# Array length

Returns the length of an array. Array length lives in the **Array** category of the `fx` menu.

## Parameter

| Parameter | Type   | Required | Default | Description                                            |
| --------- | ------ | -------- | ------- | ------------------------------------------------------ |
| Input     | string | yes      | —       | Value to transform. Previous step output or a literal. |

`Input` is the primary value (previous step output or a literal).

## Returned value

| Type     | Description                                |
| -------- | ------------------------------------------ |
| `number` | Result of the Array length transformation. |

## Limitations

- Array arguments must be valid JSON arrays. Invalid JSON or non-array values raise an error.

## Example

<details>
<summary>Get an array length</summary>

Return how many elements are in a JSON array.

1. Set **Input** to a JSON array. Paste:

   ```text title="Input"
   ["a","b","c"]
   ```

2. Confirm **Output value** is `3`.

</details>