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

# hash

The callback used to compute a hash code for keys as they are used to access, add, or remove values in the dictionary. If NULL, the collection computes a hash code by converting the pointer value to an integer. See CFDictionaryHashCallBack for a description of this callback.

## Declaration

```swift
var hash: CFDictionaryHashCallBack!
```