The relationship between the javascript comparison operator =, = and valueOf

Why strict comparison operator = will not execute Object.valueOf while generally compare operator = but execute Object.valueOf, MDN file does not see the relevant instructions in the introduction = , where can I find this part of the document? 

let num = 0;
const a = {
  valueOf: function() {
    PPnum;
    return num;
  }
};

console.log(a == 1, a.valueOf());
// false 2 , a===1  ==>  valueOf()  2 
console.log(a === 1, a.valueOf());
// false 3 , a===1  ==>  valueOf()  1
Javascript
Nov.19,2021

because of the = = operator, comparing the object with the underlying data type, the object is implicitly converted to the underlying data type. (usually valueOf followed by toString)
and = operator, if the two data types are different, they will directly return false.
give you a document address

console.log (axi1, a.valueOf ());
/ / false 3, axi1 = = > No valueOf () is performed during comparison

valueOf () is actually executed here, once in log.
and console.log (a = = 1, a.valueOf ()); is executed twice within log.
if the log is written together twice, it will be executed sequentially, and the output seen in Google browser is

.

clipboard.png

MDN

clipboard.png

so console.log (JSON.parse (JSON.stringify (a)) = = 1, a.valueOf ());
) would be friendlier.

Previous: Java multiple threads run multiple methods, why is it only a little faster than a single thread?

Next: When the mobile terminal drags, the console occasionally reports the following error?

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
© 2021 CodesHelper
Advertising Contact us About us
Menu