> ## Documentation Index
> Fetch the complete documentation index at: https://axiom.co/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# set_has_element

> This page explains how to use the set_has_element function in APL.

`set_has_element` returns true when a dynamic array contains a specific element and false when it doesn’t. Use it to perform fast membership checks on values that you have already aggregated into a set with functions such as `make_set`.

## For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.

<AccordionGroup>
  <Accordion title="Splunk SPL users">
    In Splunk, you usually call `in` for scalar membership or use multivalue functions such as `mvfind` for arrays. `set_has_element` plays the role of those helpers after you build a multivalue field with `stats values`.

    <CodeGroup>
      ```sql Splunk example theme={null}
      index=web
      | stats values(uri) AS uris BY id
      | where "/checkout" in uris
      ```

      ```kusto APL equivalent theme={null}
      ['sample-http-logs']
      | summarize uris=make_set(uri) by id
      | where set_has_element(uris, '/checkout')
      ```
    </CodeGroup>
  </Accordion>

  <Accordion title="ANSI SQL users">
    Standard SQL has no built-in array type, but dialects that implement arrays (for example PostgreSQL) use the `ANY` or `member of` operators. `set_has_element` is the APL counterpart and is applied after you build an array with `ARRAY_AGG` equivalents such as `make_set`.

    <CodeGroup>
      ```sql SQL example theme={null}
      SELECT   id
      FROM     sample_http_logs
      GROUP BY id
      HAVING   'US' = ANY(ARRAY_AGG(country));
      ```

      ```kusto APL equivalent theme={null}
      ['sample-http-logs']
      | summarize countries=make_set(['geo.country']) by id
      | where set_has_element(countries, 'US')
      ```
    </CodeGroup>
  </Accordion>
</AccordionGroup>

## Usage

### Syntax

```kusto theme={null}
set_has_element(set, value)
```

### Parameters

| Name    | Type    | Description                                                                                |
| ------- | ------- | ------------------------------------------------------------------------------------------ |
| `set`   | dynamic | The array to search.                                                                       |
| `value` | scalar  | The element to look for. Accepts `long`, `real`, `datetime`, `timespan`, `string`, `bool`. |

### Returns

A `bool` that’s true when `value` exists in `set` and false otherwise.

## Example

Use `set_has_element` to determine if a set contains a specific value.

**Query**

```kusto theme={null}
['sample-http-logs']
| extend hasElement = set_has_element(dynamic([1, 2, 3]), 2)
```

[Run in Playground](https://play.axiom.co/axiom-play-qf1k/query?initForm=%7B%22apl%22%3A%22%5B'sample-http-logs'%5D%20%7C%20extend%20hasElement%20%3D%20set_has_element\(dynamic\(%5B1%2C%202%2C%203%5D\)%2C%202\)%22%7D)

**Output**

| \_time           | hasElement |
| ---------------- | ---------- |
| May 22, 11:42:52 | true       |

## List of related functions

* [set\_difference](apl/scalar-functions/mathematical-functions/set-difference): Returns elements in the first array that aren’t in the second. Use it to find exclusions.
* [set\_union](/apl/scalar-functions/mathematical-functions/set-union): Returns the union of two or more sets. Use it when you need any element that appears in at least one set instead of every set.