# Regex
## Description
This operation allows you to extract or manipulate parts of your input strings that match a specific regular expression pattern.
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## Data types
These are the input/output expected data types for this operation:
### Input data
 - The strings from which you want to pull out specific parts.
### Output data
 - The resulting strings that match your regular expression. The output data is represented as a list of strings.
{% hint style="warning" %}
Note that the output data of this operation is a **list of strings**. Currently, Onum differentiates between `string` and `listString`, so you won't be able to use this data type in other operations that require strings as input data type.
{% endhint %}
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## Parameters
These are the parameters you need to configure to use this operation (mandatory parameters are marked with a **\***):
Regex*
Enter the RegEx pattern you want to use for matching.
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## Example
Suppose you want to **look for email addresses** in your input strings:
1. In your Pipeline, open the required [Action](https://docs.onum.com/the-workspace/pipelines/actions) configuration and select the input **Field**.
2. In the **Operation** field, choose **Regex**.
3. Set **Regex** to `[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+.[a-zA-Z]{2,}`
4. Give your **Output field** a name and click **Save**.
Entering the parameters set above, for the following text:
```
Hello, you can contact us at support@example.com or sales@company.org for assistance.
```
you'll get the following result:
```
support@example.com,sales@company.org
```
{% 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 %}