# CFDictionaryAddValue(_:_:_:) Adds a key-value pair to a dictionary if the specified key is not already present. ``` func CFDictionaryAddValue(_ theDict: CFMutableDictionary!, _ key: UnsafeRawPointer!, _ value: UnsafeRawPointer!) ``` ## Parameters `theDict` The dictionary to modify. If the dictionary is a fixed-capacity dictionary and it is full before this operation, the behavior is undefined. `key` The key for the value to add to the dictionary—a CFType object or a pointer value. The `key` is retained by the dictionary using the retain callback provided when the dictionary was created, so must be of the type expected by the callback. If a key which matches `key` is already present in the dictionary, this function does nothing (“add if absent”). `value` A CFType object or a pointer value to add to the dictionary. The `value` is retained by the dictionary using the retain callback provided when the dictionary was created, so must be of the type expected by the callback. ## Discussion --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)