# CFStringGetCharacters(_:_:_:) Copies a range of the Unicode characters from a string to a user-provided buffer. ``` func CFStringGetCharacters(_ theString: CFString!, _ range: CFRange, _ buffer: UnsafeMutablePointer!) ``` ## Parameters `theString` The string from which the characters are to be obtained. `range` The range of characters to copy. The specified range must not exceed the length of the string. `buffer` The `UniChar` buffer of length `range.length` that you have allocated on the stack or heap. On return, the buffer contains the requested Unicode characters. ## Discussion Use this function to obtain some or all of the Unicode characters represented by a CFString object. If this operation involves a large number of characters, the function call can be expensive in terms of memory. Instead you might want to consider using the in-line buffer functions [`CFStringInitInlineBuffer(_:_:_:)`](/documentation/CoreFoundation/CFStringInitInlineBuffer(_:_:_:)) and [`CFStringGetCharacterFromInlineBuffer(_:_:)`](/documentation/CoreFoundation/CFStringGetCharacterFromInlineBuffer(_:_:)) to extract the characters incrementally. --- 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)