---
title: "CFPreferencesAppSynchronize(_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfpreferencesappsynchronize(_:)"
---

# CFPreferencesAppSynchronize(_:)

Writes to permanent storage all pending changes to the preference data for the application, and reads the latest preference data from permanent storage.

## Declaration

```swift
func CFPreferencesAppSynchronize(_ applicationID: CFString) -> Bool
```

## Parameters

- `applicationID`: The ID of the application whose preferences to write to storage, typically doc://com.apple.corefoundation/documentation/CoreFoundation/kCFPreferencesCurrentApplication. Do not pass NULL or doc://com.apple.corefoundation/documentation/CoreFoundation/kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

## Return Value

Return Value true if synchronization was successful, otherwise false.

## Discussion

Discussion Calling the function CFPreferencesSetAppValue(_:_:_:) is not in itself sufficient for storing preferences. The CFPreferencesAppSynchronize(_:) function writes to permanent storage all pending preference changes for the application. Typically you would call this function after multiple calls to CFPreferencesSetAppValue(_:_:_:). Conversely, preference data is cached after it is first read. Changes made externally are not automatically incorporated. The CFPreferencesAppSynchronize(_:) function reads the latest preferences from permanent storage.

## See Also

### Synchronizing Preferences

- [CFPreferencesSynchronize(_:_:_:)](corefoundation/cfpreferencessynchronize(_:_:_:).md)