---
title: "AudioFileCountUserData(_:_:_:)"
framework: audiotoolbox
role: symbol
role_heading: Function
path: "audiotoolbox/audiofilecountuserdata(_:_:_:)"
---

# AudioFileCountUserData(_:_:_:)

Gets the number of user data items with a specified ID in a file.

## Declaration

```swift
func AudioFileCountUserData(_ inAudioFile: AudioFileID, _ inUserDataID: UInt32, _ outNumberItems: UnsafeMutablePointer<UInt32>) -> OSStatus
```

## Parameters

- `inAudioFile`: The audio file whose user data items are to be counted.
- `inUserDataID`: The four-character code (such as COMM) of the user data item.
- `outNumberItems`: On output, a pointer to the number of user data items of this type in the file.

## Return Value

Return Value A result code if there’s an error (see Result Codes) or noErr if the operation succeeds.

## Discussion

Discussion In this function, user data refers to: Chunks in AIFF, CAF, and WAVE files Resources in Sound Designer II files Other types of information in other files

## See Also

### Working with User Data

- [AudioFileGetUserDataSize(_:_:_:_:)](audiotoolbox/audiofilegetuserdatasize(_:_:_:_:).md)
- [AudioFileGetUserDataSize64(_:_:_:_:)](audiotoolbox/audiofilegetuserdatasize64(_:_:_:_:).md)
- [AudioFileGetUserData(_:_:_:_:_:)](audiotoolbox/audiofilegetuserdata(_:_:_:_:_:).md)
- [AudioFileGetUserDataAtOffset(_:_:_:_:_:_:)](audiotoolbox/audiofilegetuserdataatoffset(_:_:_:_:_:_:).md)
- [AudioFileSetUserData(_:_:_:_:_:)](audiotoolbox/audiofilesetuserdata(_:_:_:_:_:).md)
- [AudioFileRemoveUserData(_:_:_:)](audiotoolbox/audiofileremoveuserdata(_:_:_:).md)