Symbols, Iterators, Generators, and Proxies

In JavaScript development, these types are rarely used, but for some use cases, they can be very useful. In this section, we will go over what these are and how we can use them in our applications.

Symbol

Symbols are unique values; they can be used as an identifier because every time you call Symbol(), it returns a unique symbol. Even the function returns a Symbol type. However, it cannot be called using the new keyword because it is not a constructor. When stored in objects, they are not included when you iterate through the property list, so if you want to store anything as a property inside the object and do not want them to be exposed when you run JSON.stringify, you can use Symbols to achieve that.

Iterator and Generator

Iterator and Generator are often used together. Generator functions are functions whose code is not executed immediately when invoked. When a value is to be returned from the generator, it needs to be called...