Quiz · Primitive and special types · lesson 6 of 8Quiz — unknownWhat is the unknown type, and why can't you use its value directly?[A]Any value can go into unknown, but a typeof check changes nothing: inside the if the value is still typed unknown, so it can only be stored and passed on, and its methods stay closed for good.[B]Any value can be put into unknown, but an unknown value fits no specific type. You cannot call it, read its properties or index it until a check such as typeof shows what it holds. any allows all of that unchecked.[C]unknown works exactly like any for tsc: you may call it, index it and read any property. The difference is a run-time check that it adds to the JavaScript, which throws an error whenever the value turns out to be wrong.[D]unknown is the empty type: no value at all can be put into it, so a variable typed unknown never gets a value, and every read from it is an error. It exists to mark the parts of a program that never run.← BackThe unknown typeNext →void and never
