Learning TypeScript

Part IV. Extra Credit

JavaScript has been around for a few decades at this point, and people have done quite a lot of odd things with it. TypeScript’s syntax and type system need to be able to represent all those odd things to enable any JavaScript developer to work with TypeScript. As a result, there are some corners of the TypeScript language not seen in most day-to-day code but that are relevant, even necessary, for working with some kinds of projects.

I think of these parts of the language as “extra credit” in that you could avoid them entirely and still be a productive TypeScript developer. In fact, for the logical types introduced toward the end of the section, I would hope you wouldn’t need to use them very often—if at all.