---
schema_version: "1"
id: 256b637e9cacc37c3fa6410fe51eadeff021ea8c6d180db1e4f2e739a82dcd96
title: isNullType
collection: mulesoft
version: current
locale: en-us
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canonical_url: https://docs.mulesoft.com/dataweave/2.9/dw-types-functions-isnulltype
source_site: docs.mulesoft.com
content_type: documentation
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description: MuleSoft Documentation Site
release: "2.9"
latest: false
---
---
product: DataWeave
version: 2.9
---

# isNullType

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

## isNullType(t: Type): Boolean

Returns `true` if the input is the Null type.

_Introduced in DataWeave version 2.3.0._

### Parameters

<table><colgroup><col> <col></colgroup><thead><tr><th>Name</th><th>Description</th></tr></thead><tbody><tr><td><p><code>t</code></p></td><td><p>The type to check.</p></td></tr></tbody></table>

### Example

This example shows how `isNullType` behaves with different inputs.

#### Source

```DataWeave
%dw 2.0
import * from dw::core::Types
type ANull = Null
output application/json
---
{
   a: isNullType(ANull),
   b: isNullType(Null),
   c: isNullType(String),
}
```

#### Output

```Json
{
  "a": true,
  "b": true,
  "c": false
}
```