For example, in English, you might type something like:

r u going out 2nite?

Instead of:

Are you going out tonight?

How does that sort of thing work when texting in a logographic language? Is it just emoji city, or can they mix and match characters to make things more compact?

And similarly, is there a formal journalistic shorthand system that gets used when jotting down comments in real-time, e.g. in China, Korea or Japan?

Thank you kindly!