JS PROTOTYPE INHERITANCE CONCEPT
__________________________________




The JavaScript prototype property allows you to add new properties to object constructors:

function Person(first, last, age, eyecolor) {
    this.firstName = first;
    this.lastName = last;
    this.age = age;
    this.eyeColor = eyecolor;
}

Person.prototype.nationality = "English";

The JavaScript prototype property also allows you to add new methods to objects constructors:

function Person(first, last, age, eyecolor) {
    this.firstName = first;
    this.lastName = last;
    this.age = age;
    this.eyeColor = eyecolor;
}

Person.prototype.name = function () {
    return this.firstName + " " + this.lastName;
};


prototype constructor function me property ya method ko add karne ka facility deta hai 

ye js ojbect hota hai aagar object hai to isme property aur method hoga


function Person() { }

console.log(Person.prototype);

o / p

{ } --- yani ye object hai 


Special ye hai:

Jab tum likhte ho:

const p1 = new Person();


JS automatically karta hai:

p1.__proto__ = Person.prototype

prototype = ek normal object
JS us object ko new banne wale sab instances ka parent bana deta hai

Person.prototype  ← (simple object)
      ↑
__proto__
      ↑
p1
___________________________________________________________________________________


Prototype = wo object jahan se dusre objects properties inherit karte hain.
     Har prototype ke paas bhi khud ka __proto__ hota hai:

Person.prototype.__proto__ === Object.prototype
openDoor.prototype.__proto__ = events.EventEmitter.prototype;

-> yani sabi instane apne parent se ___proto__ se link rahte hai
    -> agar instance ko koi  property dekhna hota hai to wo __proto__chin ka istmmal karte hai 

ye chain last parent tak le jata  hai aur har chain ek parent level tak patchta hai aur uska
parent - level - X.prototype ko access karta hai agar waha data nahi mila to agle 
phit us parent ka __proto__ prperty ka istmmal karta hai ye series chalat hi rahai 
is comcept ka adhar par maien samaja ki

openDoor.prototype.__proto__ = events.EventEmitter.prototype;
openDoor.prototype-- - openDoor Ka contstructor storage
openDoor.prototype.__proto__-- - ye hai opendoor ke parent(papa)

events.EventEmitter----------------ye ha events ke constructor ka storage

events.EventEmitter.prototype------ya hai events ke papa

agar sabhi ko ek name convection dete hai to 
  Ram agar opendoor ka instance hai

Shayam = openDoor.prototype(ram ke father)
hanuman = events.EventEmitter.prototype(events ke father)
   
  Ram ke father shyam hai shyam aur shyam ne apna father hanuman ko bana liya hai
  ab hanuman ka sabhi data shyam ke pass hai aur shyam ko ram access ka sakata hai 
  by proto type chaining se.


    Ram (openDoor instance)
 |
    Shyam(openDoor.prototype)
    |
    Hanuman(EventEmitter.prototype)
    |
    Object.prototype

Ram ke father Shyam hai
Shyam ne apna father Hanuman ko bana liya
ab Hanuman ka sabhi data Shyam ke pass hai
aur Shyam ko Ram access kar sakta hai prototype chaining se

✅ YES — exactly 👍

Bas ek micro correction:

❌ “Hanuman ka data Shyam ke paas hai”
✅ “Shyam Hanuman se linked hai”

Data physically copy nahi hota — link hota hai.

    Honestly — ab tum concept properly grasp kar chuke ho 👏
Ye Node.js + advanced JS ka core hai.