---
title: contains() function
description: contains() tests if an array contains a specified value and returns true or false.
url: https://docs.influxdata.com/flux/v0/stdlib/universe/contains/
estimated_tokens: 1483
product: Flux
version: v0
publisher: InfluxData
canonical: https://docs.influxdata.com/flux/v0/stdlib/universe/contains/
date: '2024-04-08T16:01:02-06:00'
lastmod: '2024-04-08T16:01:02-06:00'
---

* Flux 0.19.0+

InfluxDB support

`contains()` tests if an array contains a specified value and returns `true` or `false`.

##### Function type signature

```js
(set: [A], value: A) => bool where A: Nullable
```

For more information, see [Function type signatures](/flux/v0/function-type-signatures/).

## Parameters

### value

(Required)
Value to search for.

### set

(Required)
Array to search.

## Examples

### Filter on a set of specific fields

```js
fields = ["f1", "f2"]

data
    |> filter(fn: (r) => contains(value: r._field, set: fields))
```

[](#view-example-input-and-output)

View example input and output

#### Input data

|       \_time       |\_value|\*tag|\*\_field|\_measurement|
|--------------------|-------|-----|---------|-------------|
|2021-01-01T00:00:00Z|  \-2  | t1  |   f1    |      m      |
|2021-01-01T00:00:50Z|   4   | t1  |   f1    |      m      |

|\_time|\_value|\*tag|\_measurement|\*\_field|
|------|-------|-----|-------------|---------|

|       \_time       |\_value|\*tag|\_measurement|\*\_field|
|--------------------|-------|-----|-------------|---------|
|2021-01-01T00:00:10Z|   4   | t2  |      m      |   f1    |
|2021-01-01T00:00:20Z|  \-3  | t2  |      m      |   f1    |
|2021-01-01T00:00:50Z|   1   | t2  |      m      |   f1    |

|\_time|\_value|\*tag|\*\_field|\_measurement|
|------|-------|-----|---------|-------------|

|       \_time       |\_value|\*tag|\*\_field|\_measurement|
|--------------------|-------|-----|---------|-------------|
|2021-01-01T00:00:10Z|  10   | t1  |   f2    |      m      |
|2021-01-01T00:00:20Z|   7   | t1  |   f2    |      m      |

|       \_time       |\_value|\*tag|\*\_field|\_measurement|
|--------------------|-------|-----|---------|-------------|
|2021-01-01T00:00:30Z|  17   | t1  |   f3    |      m      |
|2021-01-01T00:00:40Z|  15   | t1  |   f3    |      m      |

|\_time|\_value|\*tag|\_measurement|\*\_field|
|------|-------|-----|-------------|---------|

|       \_time       |\_value|\*tag|\_measurement|\*\_field|
|--------------------|-------|-----|-------------|---------|
|2021-01-01T00:00:00Z|  19   | t2  |      m      |   f3    |
|2021-01-01T00:00:30Z|  19   | t2  |      m      |   f3    |
|2021-01-01T00:00:40Z|  13   | t2  |      m      |   f3    |

#### Output data

|       \_time       |\_value|\*tag|\*\_field|\_measurement|
|--------------------|-------|-----|---------|-------------|
|2021-01-01T00:00:00Z|  \-2  | t1  |   f1    |      m      |
|2021-01-01T00:00:50Z|   4   | t1  |   f1    |      m      |

|\_time|\_value|\*tag|\_measurement|\*\_field|
|------|-------|-----|-------------|---------|

|       \_time       |\_value|\*tag|\_measurement|\*\_field|
|--------------------|-------|-----|-------------|---------|
|2021-01-01T00:00:10Z|   4   | t2  |      m      |   f1    |
|2021-01-01T00:00:20Z|  \-3  | t2  |      m      |   f1    |
|2021-01-01T00:00:50Z|   1   | t2  |      m      |   f1    |

|\_time|\_value|\*tag|\*\_field|\_measurement|
|------|-------|-----|---------|-------------|

|       \_time       |\_value|\*tag|\*\_field|\_measurement|
|--------------------|-------|-----|---------|-------------|
|2021-01-01T00:00:10Z|  10   | t1  |   f2    |      m      |
|2021-01-01T00:00:20Z|   7   | t1  |   f2    |      m      |

#### Related

* [Work with arrays](/flux/v0/data-types/composite/array/)
| _time | _value | *tag | *_field | _measurement |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | *_field | _measurement |
| 2021-01-01T00:00:00Z | -2 | t1 | f1 | m |
| 2021-01-01T00:00:50Z | 4 | t1 | f1 | m |

| _time | _value | *tag | _measurement | *_field |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | _measurement | *_field |

| _time | _value | *tag | _measurement | *_field |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | _measurement | *_field |
| 2021-01-01T00:00:10Z | 4 | t2 | m | f1 |
| 2021-01-01T00:00:20Z | -3 | t2 | m | f1 |
| 2021-01-01T00:00:50Z | 1 | t2 | m | f1 |

| _time | _value | *tag | *_field | _measurement |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | *_field | _measurement |

| _time | _value | *tag | *_field | _measurement |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | *_field | _measurement |
| 2021-01-01T00:00:10Z | 10 | t1 | f2 | m |
| 2021-01-01T00:00:20Z | 7 | t1 | f2 | m |

| _time | _value | *tag | *_field | _measurement |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | *_field | _measurement |
| 2021-01-01T00:00:30Z | 17 | t1 | f3 | m |
| 2021-01-01T00:00:40Z | 15 | t1 | f3 | m |

| _time | _value | *tag | _measurement | *_field |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | _measurement | *_field |

| _time | _value | *tag | _measurement | *_field |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | _measurement | *_field |
| 2021-01-01T00:00:00Z | 19 | t2 | m | f3 |
| 2021-01-01T00:00:30Z | 19 | t2 | m | f3 |
| 2021-01-01T00:00:40Z | 13 | t2 | m | f3 |

| _time | _value | *tag | *_field | _measurement |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | *_field | _measurement |
| 2021-01-01T00:00:00Z | -2 | t1 | f1 | m |
| 2021-01-01T00:00:50Z | 4 | t1 | f1 | m |

| _time | _value | *tag | _measurement | *_field |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | _measurement | *_field |

| _time | _value | *tag | _measurement | *_field |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | _measurement | *_field |
| 2021-01-01T00:00:10Z | 4 | t2 | m | f1 |
| 2021-01-01T00:00:20Z | -3 | t2 | m | f1 |
| 2021-01-01T00:00:50Z | 1 | t2 | m | f1 |

| _time | _value | *tag | *_field | _measurement |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | *_field | _measurement |

| _time | _value | *tag | *_field | _measurement |
| --- | --- | --- | --- | --- |
| _time | _value | *tag | *_field | _measurement |
| 2021-01-01T00:00:10Z | 10 | t1 | f2 | m |
| 2021-01-01T00:00:20Z | 7 | t1 | f2 | m |