Types of Memory

1. Stack Memory

Stack Memory are Small in Size , It is faster , we store primitive data here , it works in Last In, First Out (LIFO) manner

2. Heap Memory

Heap Memory are Large in Size , It is slower , we store data by its reference here

Object

Object are non primitive data type ,that stores data in key value pairs. it is stored in heap memory by reference.

syntax

const human{
key : value,

}

How object store in Memory In Js

When an object is created in JavaScript, the actual data of the object is stored in heap memory.

The stack memory holds the variables and the references to the objects that live in the heap.

What happen when we copy object into another object

CODE-

 let p = {
name: "aryan"
}

let q = p ; // Address of p in heap memory getting stored in q variable

q.name = "kumar"

console.log(p.name) // output is "kumar"

Now Lets understand Code

As you can see in line let q = p ; we are storing address of object p in q , due to this one major problem arising that is now p and q both accessing same location so both can make change.

This arise a major problem in coping Object.

Then how to Copy object without making both of them pointing to same location in heap memory

1. For this we can use spread operator (...), spread operator iteratively copy object by value.
   const k = { ...p } // syntax

   One major problem with spread operator is that it Shallow Copy Javascript object meaning it will not copy by value if there is nested object which leads to same problem as both variables will point to same location of nested object

2. To tackle this we need to Deep Copy Object meaning we will copy object by passing only value (even for nested object) to another variable

   To do so we will JSON Serialization and Unserialization of Objects in JavaScript

   1. Use JSON.stringify to Serialisation

    const person = {
    name: "Aryan",
   
    address: {
    country: "India"
    }
    };
    const person2 = JSON.stringify(person);
   
    // Output: '{"name":"Aryan","address":{"country":"India"}}'
   

   2. Use JSON.parse(jsonString) to Unserialization

    const anotherperson = JSON.parse(person2); // now value of person is deep copies in anotherperson
   

JSON Serialization and Unserialization of Human Body
( Teleport hona iss ko tho Khate hai )

Conclusion:

Imagine teleportation as converting a person into data, sending that data to another place, and then rebuilding the person exactly as they were. JSON serialization and deserialization work in a similar way.

Key terminology

1. Garbage Collection - > Js has Garbage Collection , it free up space in heap memory which are no longer in used by object

2. Memory leak → A memory leak occurs when a program fails to release memory that is no longer needed.