> For the complete documentation index, see [llms.txt](https://docs.onum.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.onum.com/pipelines/actions/transformation/field-transformation/field-transformation-operations/list-manipulation/count-list-boolean.md).

# Count list boolean

## Description

This operation counts the number of elements in a given list of booleans.

***

## Data types

These are the input/output expected data types for this operation:

### Input data

`ListBoolean` - The input lists of booleans.

### Output data <a href="#output-data" id="output-data"></a>

`Integer` - Number of elements in the input lists.

***

## Example

Suppose you want to **count the number of elements in your input list of booleans**:

1. In your Pipeline, open the required [Action](/pipelines/actions.md) configuration and select the input **Field**.
2. In the **Operation** field, choose **Count list boolean**.
3. Give your **Output field** a name and click **Save**. You'll get the number of elements in your input boolean lists. For example:

```
Input data - true, false

Output data - 2
```

{% hint style="info" %}
You can try out operations with specific values using the **Input** field above the operation. You can enter the value in the example above and check the result in the **Output** field.
{% endhint %}