The JavaScript exception "missing variable name" is a common error. It is usually caused by omitting a variable name or a typographic error.

The JavaScript exception "SyntaxError: private fields can't be deleted" occurs when delete is used on a private element of a class or an object.

The JavaScript exception "functions cannot be labelled" occurs when a function declaration has a label before it.

The Uint8Array.fromHex() static method creates a new Uint8Array object from a hexadecimal string.

The __lookupSetter__() method of Object instances returns the function bound as a setter to the specified property.

The bitwise AND assignment operator `&=`.

The Function() constructor creates Function objects. Calling the constructor directly can create functions dynamically, but suffers from security and similar (but far less significant) performance issues as eval(). However, unlike eval (which may have access to the local scope), the Function constructor creates functions which execute in the global scope only.

Iterator over the entries in a directory.

The Reflect.get() static method is like the property accessor syntax, but as a function.

The Proxy() constructor creates Proxy objects.