js & object & prototype & __proto__ & prototype chain

js & object & prototype & proto & prototype chain

constructor prototype === instance proto

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Inheritance_and_the_prototype_chain

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/proto

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/prototype

let log = console.log;

function Foo() {
    name: "Foo";
}

// var foo = new Foo();
let foo = new Foo();

log(Foo.name);
log(foo.name);

log(`Foo.prototype =`, Foo.prototype);
log(`foo.prototype =`, foo.prototype);

log(`Foo.__proto__ =`, Foo.__proto__);
log(`foo.__proto__ =`, foo.__proto__);

log(`Foo.prototype === foo.__proto__`, Foo.prototype === foo.__proto__);

"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 * @created 2019-08-16
 *
 * @description prototype-chain (prototype & __proto__ )
 * @augments
 * @example
 * @link https://hackernoon.com/understand-nodejs-javascript-object-inheritance-proto-prototype-class-9bd951700b29
 *
 */

let log = console.log;

function Foo() {
    name: "Foo";
}

// var foo = new Foo();
let foo = new Foo();

log(Foo.name);
// Foo

log(foo.name);
// undefined

log(`Foo.prototype =`, Foo.prototype);
// {constructor: ƒ}
// constructor: ƒ Foo()
// __proto__: Object
log(`foo.prototype =`, foo.prototype);
// undefined

log(`Foo.__proto__ =`, Foo.__proto__);
//  ƒ () { [native code] }
log(`foo.__proto__ =`, foo.__proto__);
// {constructor: ƒ}
// constructor: ƒ Foo()
// __proto__: Object

log(`Foo.prototype === foo.__proto__`, Foo.prototype === foo.__proto__);
// true

https://hackernoon.com/understand-nodejs-javascript-object-inheritance-proto-prototype-class-9bd951700b29

https://stackoverflow.com/questions/9959727/proto-vs-prototype-in-javascript

https://www.freecodecamp.org/news/prototype-in-js-busted-5547ec68872/

( new Foo ).__proto__ === Foo.prototype;
( new Foo ).prototype === undefined;

function Point(x, y) {
    this.x = x;
    this.y = y;
}

var myPoint = new Point();

// the following are all true
myPoint.__proto__ == Point.prototype
myPoint.__proto__.__proto__ == Object.prototype
myPoint instanceof Point;
myPoint instanceof Object;

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xgqfrms 2012-2020

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