Supplies the language for a token, if one can be determined.
- iOS 5.0+
- macOS 10.7+
- tvOS 9.0+
- watchOS 2.0+
Each value for this tag scheme is a BCP-47 language identifier. For example, the language identifier for English is "en" and the identifier for Chinese written using the Simplified Chinese script is "zh-Hans". The identifier "und" is used if a specific language cannot be determined.
The tagger generally attempts to determine the language of text at the level of an entire sentence, paragraph, or document, rather than word by word.