Quickly obtains a pointer to a C-string buffer containing the characters of a string in a given encoding.
- iOS 2.0+
- macOS 10.0+
- UIKit for Mac 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
- Core Foundation
The string whose contents you wish to access.
The string encoding to which the character contents of
theshould be converted. The encoding must specify an 8-bit encoding.
A pointer to a C string or
NULL if the internal storage of
the does not allow this to be returned efficiently.
This function either returns the requested pointer immediately, with no memory allocations and no copying, in constant time, or returns
NULL. If the latter is the result, call an alternative function such as the
CFString function to extract the characters.
Whether or not this function returns a valid pointer or
NULL depends on many factors, all of which depend on how the string was created and its properties. In addition, the function result might change between different releases and on different platforms. So do not count on receiving a non-
NULL result from this function under any circumstances.