# init(charactersNoCopy:length:freeWhenDone:) Returns an initialized `NSString` object that contains a given number of characters from a given C array of UTF-16 code units. ``` convenience init(charactersNoCopy characters: UnsafeMutablePointer, length: Int, freeWhenDone freeBuffer: Bool) ``` ## Parameters `characters` A C array of UTF-16 code units. `length` The number of characters to use from `characters`. `freeBuffer` If , the receiver releases the memory with `free()` when it no longer needs the data; if it won’t. ## Return Value An initialized `NSString` object that contains `length` characters from `characters`. The returned object may be different from the original receiver. ## Discussion If an error occurs during the creation of the string, then `bytes` is not freed even if `flag` is . In this case, the caller is responsible for freeing the buffer. This allows the caller to continue trying to create a string with the buffer, without having the buffer deallocated. ## See Also [`+ stringWithCharacters:length:`](/documentation/Foundation/NSString/stringWithCharacters:length:) Returns a string containing a given number of characters taken from a given C array of UTF-16 code units. --- 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)