Summary: What is hosting? JavaScript Hoisting refers to the process whereby the interpreter appears to move the declaration of functions, variables, classes, or imports to the top of their scope, prior to execution of the code. const and let can not access the value before initialization because they are placed in a temporal dead zone. But in var case, it will give undefined. But in function, we get values of function because function values are stored during the memory creation phase so we just get access to it. this much I understood from this video. *Correct me if I am wrong.
Always is used to confuse between undefined and not defined. Got it clear. * undefined is not an error, it is a datatype - thinks to remember for beginners
Best way of explaning thanks saw so many videos on this topic all are saying hoisting is to move the declarations to the top but you explained in detail how javascript hoisting is working in background thanks for making this video😊
00:02 Hoisting in JavaScript is a commonly asked topic in interviews 02:46 Hoisting in JavaScript moves variable and function declarations to the top of their containing scope. 04:39 Hoisting in JavaScript allows accessing variables before their declaration without errors. 07:15 JavaScript hoists variable and function declarations 09:39 Hoisting in JavaScript allows function and class declarations to be accessed before they are defined. 11:56 Function declaration hoisting in JavaScript 14:19 Hoisting in JavaScript allows function declarations to be moved to the top of the code. 16:48 Hoisting in JavaScript explained 19:27 Understanding function declaration, definition, and hoisting in JavaScript 21:51 Hoisting is a process of moving variable and function declarations to the top in JavaScript 23:49 Understanding function declaration vs. function definition Crafted by Merlin AI.
Sir, function expression m jab uss function ko call krte h tab uski memory allocation phase nhi hoti kya..kyuki debugger lga n k baad jab function call krte h toh wo variable tab tak nhi dikhata jab tak usme variable assign na ho..esa kyu hota h?
Hi sir , You just explained everything in detailed really like how you explain. Just had one doubt As we know var , let , const all are hoisted but let and const go yo temporal dead zone and we cannot access it until it is initialized. Now just will give 3 examples Eg 1 Let a = 0 Console.log(a) Output = 0 Eg 2 Console.log(a) Let a= 3: Output : cannot access a before initialization. Eg 3 Let a; Console.log(a) a=2; Output : undefined I understood 2nd but 3rd as during memory allocation phase a will be undefined and as its declare using let it will go to temporal dead zone and we cannot accept until it is assigned with value , so in this case how we are getting undefined.
In your third example , javascript engine automatically initialized a variable during memory execution phase with undefined value. Hence it is out of TDZ . 😊
For let and const there will be temporary dead zone if we use them before " declaration".....we need to see "declaration" not "initialisation".......... In 3rd example you are getting the output because there is no temporal zone created as we are using the variable after declaration
Bhaiya apka js course kafi depth hai kahi kahi hame kuch chije hard lagti hai pr itni achi aur good knowledge Jo intrw time pr kafi important hoti hai ... Voh sab hame abhi hi samjh AA rhi h aur Bhaiya Maine js aur bhi channel se study ki hai pr yaha aake Aisa kyu lgta hai ki voh bs hame js project base dikhate h 😂😢 Itni good knowledge ap hame free mai provide Kara rhe ho thankyou so much sir ❤❤❤ ❤❤ 😅😊 And bhaiya mere vs console me voh variable adress search nhi ho rha hai 😢ky Karu Mai ek din bhi kafi preshan ho gya Matlb jese apne variable adress search Kiya h vese mere mai variable adress search karne wala option hi nhi AA rha hai bottom side mai 😢 ky Karu btao na bhaiya pls 😢
Sir us line ko kya bole ge jaha pe code execution ho jata like var a line me to undefined hota hai uske next line me jab jata hai tab exicute hota hai to us next line ko kya bole ge
badhiya video h bhai...but ye code snippet dekho, kya reason h alg alag output ka yha? strict mode disabled h var x = "a"; if (true) { x = "b"; function x() {} } console.log(x); //ƒ x() {} var x = "a"; if (true) { function x() {} x = "b"; } console.log(x); // "b"
Hoisting mein var aur functions declaration upar shift hone jaisa appear krte hain pr in reality woh upar shift nhi hote hain. Hoisting mtlb variable can be accessed before it is declared and initialized.
Summary:
What is hosting?
JavaScript Hoisting refers to the process whereby the interpreter appears to move the declaration of functions, variables, classes, or imports to the top of their scope, prior to execution of the code.
const and let can not access the value before initialization because they are placed in a temporal dead zone. But in var case, it will give undefined.
But in function, we get values of function because function values are stored during the memory creation phase so we just get access to it.
this much I understood from this video.
*Correct me if I am wrong.
Always is used to confuse between undefined and not defined. Got it clear.
* undefined is not an error, it is a datatype - thinks to remember for beginners
Awesome, I'm glad you learn something new.
Keep Learning and Sharing 😊
Best way of explaning thanks
saw so many videos on this topic all are saying hoisting is to move the declarations to the top but you explained in detail how javascript hoisting is working in background thanks for making this video😊
Awesome, keep learning and sharing 😊
00:02 Hoisting in JavaScript is a commonly asked topic in interviews
02:46 Hoisting in JavaScript moves variable and function declarations to the top of their containing scope.
04:39 Hoisting in JavaScript allows accessing variables before their declaration without errors.
07:15 JavaScript hoists variable and function declarations
09:39 Hoisting in JavaScript allows function and class declarations to be accessed before they are defined.
11:56 Function declaration hoisting in JavaScript
14:19 Hoisting in JavaScript allows function declarations to be moved to the top of the code.
16:48 Hoisting in JavaScript explained
19:27 Understanding function declaration, definition, and hoisting in JavaScript
21:51 Hoisting is a process of moving variable and function declarations to the top in JavaScript
23:49 Understanding function declaration vs. function definition
Crafted by Merlin AI.
I have seen a first time a youtuber who always reply (or give heart) on the viewer's comment.. I really appreciate it bhaiya..
Thank you ❤️
Clear explanation with proof 👍🏻
Very nicely explained! My memory creation phase is running at full speed now!
Day 11: video 32 completed ....thank you sir making such great video 😊
Anurag bhai on fire.....❤🔥❤🔥❤🔥❤🔥❤🔥❤🔥
i like it....... i like this video also now total like is =70....this guy deserve more like and subscriber...
🎉🎉🎉 bhot Hi Simple Way me Explain kardiya ❤❤❤ 10 out of 100 💯💯💯💯😁
I felt it, when you said, @24:05 anonymous ki spelling bahut khatarnak hoti h(CBSE wale is pain ko kabhi nhi samajh sakte.)
😀😀
awesome sir , ky bolu sir sabd nhi hai bolne ke liya , aap itna aacha padte hai , love u
❤️❤️
anonymous ki spelling bahut khatarnaak hoti hai 24:00, waah bhaiya maje aate hai video dekhte samay, baaki clear cut this topic...🤣🤣😂😂
😀😀
Sir, function expression m jab uss function ko call krte h tab uski memory allocation phase nhi hoti kya..kyuki debugger lga n k baad jab function call krte h toh wo variable tab tak nhi dikhata jab tak usme variable assign na ho..esa kyu hota h?
Simple and good easy to understand
Wah Sir poora concept clear❤
Awesome lecture ☺️ sir.
Thanks 😊
Episode 32 completed bhaiya ji❤
Very good resoucre you are , i wonder why this video has only 2k view
Hi sir ,
You just explained everything in detailed really like how you explain.
Just had one doubt
As we know var , let , const all are hoisted but let and const go yo temporal dead zone and we cannot access it until it is initialized.
Now just will give 3 examples
Eg 1
Let a = 0
Console.log(a)
Output = 0
Eg 2
Console.log(a)
Let a= 3:
Output : cannot access a before initialization.
Eg 3
Let a;
Console.log(a)
a=2;
Output : undefined
I understood 2nd but 3rd as during memory allocation phase a will be undefined and as its declare using let it will go to temporal dead zone and we cannot accept until it is assigned with value , so in this case how we are getting undefined.
In your third example , javascript engine automatically initialized a variable during memory execution phase with undefined value. Hence it is out of TDZ . 😊
This is a good point. I'll make a video on it and explain in detail.
For let and const there will be temporary dead zone if we use them before " declaration".....we need to see "declaration" not "initialisation".......... In 3rd example you are getting the output because there is no temporal zone created as we are using the variable after declaration
Well explained ! Thank you bhaiya !
hi...memory declaration phase ko hi hoisting khte hai ??
Bhaiya apka js course kafi depth hai kahi kahi hame kuch chije hard lagti hai pr itni achi aur good knowledge Jo intrw time pr kafi important hoti hai ... Voh sab hame abhi hi samjh AA rhi h aur
Bhaiya Maine js aur bhi channel se study ki hai pr yaha aake Aisa kyu lgta hai ki voh bs hame js project base dikhate h 😂😢
Itni good knowledge ap hame free mai provide Kara rhe ho thankyou so much sir ❤❤❤
❤❤ 😅😊
And bhaiya mere vs console me voh variable adress search nhi ho rha hai 😢ky Karu Mai ek din bhi kafi preshan ho gya
Matlb jese apne variable adress search Kiya h vese mere mai variable adress search karne wala option hi nhi AA rha hai bottom side mai 😢 ky Karu btao na bhaiya pls 😢
revision done bhaiya.
Kha gya mahara MDN, Aaja MDN😁😁, Love you bhai yrrr mja aa gya aapse pdne me to
Awesome, keep learning and growing 😊
anonymous ki spelling bahot khatranaak hoti hai 🤣🤣🤣
😀😀
Sahi bat hai
Sir us line ko kya bole ge jaha pe code execution ho jata like var a line me to undefined hota hai uske next line me jab jata hai tab exicute hota hai to us next line ko kya bole ge
badhiya video h bhai...but ye code snippet dekho, kya reason h alg alag output ka yha? strict mode disabled h
var x = "a";
if (true) {
x = "b";
function x() {}
}
console.log(x); //ƒ x() {}
var x = "a";
if (true) {
function x() {}
x = "b";
}
console.log(x); // "b"
Very nice sir
Awesome, keep learning and sharing 😊
One doubt sir🤚 Is there no memory execution phase for const or let ?
There is
@@procodrr thank you sir
Hoisting mein var aur functions declaration upar shift hone jaisa appear krte hain pr in reality woh upar shift nhi hote hain. Hoisting mtlb variable can be accessed before it is declared and initialized.
Bilkul
god of js😇
Can you give a clear definition of hosting
Again thank you.
itna din ke baad hoisting kya hai wo samaj mein aya hein.
day 3 @ vid 35
great
sir Dsa le k ayoo fast
Theory complete
Sir why can't you make it in English 😢 i Regularly watch your interview sessions i gained lots of knowledge from that, But here language barrier 😢
done ep32
💯
❤❤❤
Immediately invoke function (function {}());
Correct 👍
Iife
day three
Hoisting
❤