# CFStringCreateWithCString(_:_:_:) Creates an immutable string from a C string. ``` func CFStringCreateWithCString(_ alloc: CFAllocator!, _ cStr: UnsafePointer!, _ encoding: CFStringEncoding) -> CFString! ``` ## Parameters `alloc` The allocator to use to allocate memory for the new string. Pass `NULL` or [`kCFAllocatorDefault`](/documentation/CoreFoundation/kCFAllocatorDefault) to use the current default allocator. `cStr` The `NULL`-terminated C string to be used to create the CFString object. The string must use an 8-bit encoding. `encoding` The encoding of the characters in the C string. The encoding must specify an 8-bit encoding. ## Return Value An immutable string containing `cStr` (after stripping off the `NULL` terminating character), or `NULL` if there was a problem creating the object. Ownership follows the [The Create Rule](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/Concepts/Ownership.html#//apple_ref/doc/uid/20001148-103029). ## Discussion A C string is a string of 8-bit characters terminated with an 8-bit `NULL`. Unichar and Unichar32 are not considered C strings. --- 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)