---
schema_version: "1"
id: 838d2b49494010a77ea6ea1ccff36959762736e7894a49e05f71ed4626d7b558
title: functionParamTypes
collection: mulesoft
version: current
locale: en-us
portal_url: https://docs.salesforce.com/mulesoft/current/en-us/dataweave/2.3/dw-types-functions-functionparamtypes.md
canonical_url: https://docs.mulesoft.com/dataweave/2.3/dw-types-functions-functionparamtypes
source_site: docs.mulesoft.com
content_type: documentation
content_hash: 0198713cbabb162e6293f9ab47cbe0b6057deb1b6915623e0026df7f263b4005
description: MuleSoft Documentation Site
release: "2.3"
latest: false
---
---
product: DataWeave
version: 2.3
---

# functionParamTypes

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

## functionParamTypes(Type): Array<FunctionParam>

Returns the list of parameters from the given function type. This function fails if the provided
type is not a Function type.

_Introduced in DataWeave 2.3.0. Supported by Mule 4.3 and later._

### Parameters

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

### Example

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

#### Source

```DataWeave
%dw 2.0
output application/json
import * from dw::core::Types
type AFunction = (String, Number) -> Number
type AFunction2 = () -> Number
---
{
    a: functionParamTypes(AFunction),
    b: functionParamTypes(AFunction2)
}
```

#### Output

```Json
 {
    "a": [
      {
        "paramType": "String",
        "optional": false
      },
      {
        "paramType": "Number",
        "optional": false
      }
    ],
    "b": [

    ]
  }
```