---
title: release
framework: corefoundation
role: symbol
role_heading: Instance Property
path: corefoundation/cfdictionarykeycallbacks/release
---

# release

The callback used to release keys as they are removed from the dictionary. If NULL, keys are not released. See CFDictionaryReleaseCallBack for a description of this callback.

## Declaration

```swift
var release: CFDictionaryReleaseCallBack!
```