NoGlobalObject

Misconception:

Using the keyword this outside specific scopes yields undefined, as there is no global object.

There isn't a global object

There is always a global object

Before starting the execution, JavaScript creates a global object.

When we use the keyword this outside specific environments it always refers to this global object.

globalThis

JavaScript can run in very different contexts (a browser, a Web Worker, NodeJS, and so on…) and each of them used to have a special keyword to refer to the global object (window, self, global). Newer versions of the JavaScript specification have standardized globalThis as the proper way to refer to the global object from anywhere in the code.

JavaScript

ecma11

12.2.2 The this Keyword

ecma11

18 The Global Object

Object Scope