Creates an immutable string from a segment (substring) of an existing string.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
- Core Foundation
The allocator to use to allocate memory for the new string. Pass
kto use the current default allocator.
The string from which to create the new string.
The range of characters in
strto copy. The specified range must not exceed the length of the string.
An immutable string, or
NULL if there was a problem creating the object. Ownership follows the The Create Rule.