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[JS] typeof null, null instanceof Object 본문

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[JS] typeof null, null instanceof Object

optimy 2021. 7. 13. 01:53 
typeof null; // object

null instanceof Object; // false

null은 어떤 값이 '비어있음(absense)'을 나타낸다.
primitive value 이며 falsy 한 값으로 취급된다.

https://262.ecma-international.org/5.1/#sec-11.4.3

 

ECMAScript Language Specification - ECMA-262 Edition 5.1

This section contains a non-normative overview of the ECMAScript language. ECMAScript is an object-oriented programming language for performing computations and manipulating computational objects within a host environment. ECMAScript as defined here is not

262.ecma-international.org

https://stackoverflow.com/questions/28956060/javascript-confusing-syntax-inconsistence-for-null-instanceof-and-typeof

 

Javascript confusing syntax inconsistence for null, instanceof and typeof?

var obj = {}; typeof obj; // returns "object" obj instanceof Object // return true typeof null // returns "object" null instanceof Object // returns false And how about typeof undefined // retu...

stackoverflow.com

 

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