---
title: "parameter(withID:scope:element:)"
framework: audiotoolbox
role: symbol
role_heading: Instance Method
path: "audiotoolbox/auparametertree/parameter(withid:scope:element:)"
---

# parameter(withID:scope:element:)

Searches the tree for a specific version 2 audio unit parameter.

## Declaration

```swift
func parameter(withID paramID: AudioUnitParameterID, scope: AudioUnitScope, element: AudioUnitElement) -> AUParameter?
```

## Parameters

- `paramID`: The parameter ID with which to search the tree.
- `scope`: The scope with which to search the tree.
- `element`: The element with which to search the tree.

## Return Value

Return Value The parameter corresponding to the supplied ID, scope, and element. Returns nil if the parameter is nonexistent or if it is not associated with a version 2 audio unit.

## Discussion

Discussion Version 2 audio units publish parameters identified by a parameter ID, scope, and element. A host that knows that it is dealing with a version 2 audio unit can locate parameters using this method—for example, for the Apple-supplied system audio units.

## See Also

### Obtaining Tree Parameters

- [parameter(withAddress:)](audiotoolbox/auparametertree/parameter(withaddress:).md)