# CFBundleCopyLocalizedString(_:_:_:_:) Returns a localized string from a bundle’s strings file. ``` func CFBundleCopyLocalizedString(_ bundle: CFBundle!, _ key: CFString!, _ value: CFString!, _ tableName: CFString!) -> CFString! ``` ## Parameters `bundle` The bundle to examine. `key` The key for the localized string to retrieve. This key will be used to look up the localized string in the strings file. Typically the key is identical to the value of the localized string in the development language. `value` A default value to return if no value exists for `key`. `tableName` The name of the strings file to search. The name should not include the `strings` filename extension. The case of the string must match that of the file name, even on file systems (such as HFS+) that are not case sensitive with regards to file names ## Return Value A CFString object that contains the localized string. If no value exists for `key`, returns `value` unless `value` is `NULL` or an empty string, in which case `key` is returned instead. 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 This is the base function from which the other localized string macros are derived. In general you should not use this function because the `genstrings` development tool only recognizes the macro version of this call when generating strings files. See [`CFCopyLocalizedString`](/documentation/CoreFoundation/CFCopyLocalizedString) for details on how to use these macros. --- 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)