JS의 전역 객체

About

Every JavaScript environment has one special object called the global object. It has features like: –

• setTimeout
• console
• Math
• Date
• Array
• JSON
• parseInt

Conceptually, both the below code blocks are same.

// For Example:
console.log(Math.PI);
console.log(setTimeout);
console.log(Date);

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&&

globalObject.Math
globalObject.Date
globalObject.console

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History

In the browser, it is called window.

window.Math === Math
// true

window.Date === Date
// true

window.console === console
// true

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In a run time environment like Node, it is called global.

global.setTimeout
global.console
global.Buffer

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However, in workers, it was called self.
So to make it less annoying,
ES20, introduced globalThis.

1. For Browsers, javascript globalThis === window // true javascript

2. For run time environments
   

   globalThis === global
   // true
   

3. For web workers
   

   globalThis === self
   // true