Character represents a set of Unicode-compliant characters. Foundation types use
Character to group characters together for searching operations, so that they can find any of a particular set of characters during a search.
- iOS 10.0+
- macOS 10.12+
- tvOS 10.0+
- watchOS 3.0+
- Xcode 8.0+
This type provides “copy-on-write” behavior, and is also bridged to the Objective-C