Why does prototype inheritance in the prototype chain have such a different result?

< H2 > purpose: < / H2 > 
ABBCBObjectC?
< H2 > my understanding: < / H2 > 
prototypenew B(),Anew B()__proto__BBnew C() ?

the first way to write:


:


Javascript
Mar.13,2021

js has variable improvement, so the first paragraph is equivalent to 

function A () {
  
}
function B () {

}
function C () {
  
}
var aObj;
A.prototype = new B(); // ABobject
A.prototype.constructor = A;

B.prototype = new C();
B.prototype.constructor = B; // B

// A.prototype = new B(); // newBC.prototype

aObj = new A();
console.log(aObj);

Update:
your puzzle may be that if I change the prototype property of a method, will the original new object automatically update the prototype object? 

function B () {}
let b = new B()
console.log(b.__proto__ === B.prototype) // true
B.prototype = {} // B
console.log(b.__proto__ === B.prototype) // falsenew

Abstract the above process and change it to the following: 

console.log(b.__proto__ === B.prototype) // true
B.prototype = {} // B
console.log(b.__proto__ === B.prototype) // false

simplify, use c instead of b.protoplast , d instead of B.prototype : 

console.log(c === d) // true
d = {}
console.log(c === d) // false

that is, at first c and d point to the same object, and then make d point to another object, then will c automatically update to point to the new object?
answer: why is it updated automatically?

Previous: Element vue uses version 1.x of the dropdown component to report an error

Next: Excuse me, how do I get the x, y values in this case?

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
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3975a-34561.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3975a-34561.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?