知识点摘要:
An arrow function does not have its own this; the this value of the enclosing execution context is used.
Arrow functions do not have a prototype property.
(1)Arrow functions cannot be used as constructors and will throw an error when used with new.
(2) Since arrow functions do not have their own this, the methods call() or apply() can only pass in parameters. thisArg is ignored.
(3) Arrow functions do not have their own arguments object. Thus, arguments is simply a reference to the arguments of the enclosing scope.
(4) arrow functions cannot be used as generators.