How To Handle Errors in JavaScript 

Thank you Khan. Generics are types, so instead of passing a type like string to a class/function/interface that accepts a generic, you can pass another generic. So it becomes like a chain. To understand 3rd party libraries you need to read the type definition files. Type definition files are files that usually have this naming format *.d.ts You can read those files whenever you import some type from them by clicking right ctrl button and click on the imported type. Sometimes they are better than the documentations, saving you time and also you practice TypeScript concepts beyond simply typing basic arguments and functions from a package, which is what happens when you use TypeScript most of the time.