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Prototype Property in JS

When a new function is created a new property is added to it. That property is named prototype. It's an object and initially has two properties:

• constructor: which points to the function itself;
• __proto__

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What is dunder proto in JS

dunder proto === __proto__

Every object in JS has this property.

It points back to the prototype object of the constructor function that created that object.

Only Object.prototype.__proto__ === null

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What is an Instance in JS?

This is the object which is created from a constructor function.

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Static methods in JS "Classes"

Methods that must be invoked on the class itself, not on its instances

class Human {
  constructor(name) {
    this.name = name;
  }
 

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"Inheritance" in JS

class Human {
    constructor(name) {
        this.name = name
    }
   
}

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Rest parameters

function logNumbers(...args) {
  console.log(args); // type: array
}

logNumbers(1,2)
// [1, 2]

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Classes in TypeScript

Types of properties

• public(the default case)
• private
  • you can only access it from the class. Cannot set/read it from outside.

  class Human {
    private type: string = "terran";
    constructor(public name: string) {
  

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Object.create

const person = {
  name: null
}

// create new object and set its __proto__ to point to person object
const ivan = Object.create(person);

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Object.defineProperty

Todo

MDN

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hasOwnProperty

const person = {
  name: null
}

// create new object and set its __proto__ to point to person object
const ivan = Object.create(person);