The Scope Chain, 🔥Scope & Lexical Environment | Namaste JavaScript Ep. 7

[@avinashsingha6056]

Not even a paid course comes close to the quality and content of these videos ...looking forward for future videos

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♥️

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Indeed he's soooo goodddd!!!!!!

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@Aldo Mosty HAHAHAHAHAHAHHA

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I just took screenshot of this wonderful comment which is posted in a wonderful video by wonderful content creator.

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That's true 👍🏻

[@kirtikhohal5025]

Summary : 1. Scope of a variable is directly dependent on the lexical environment. 2. Whenever an execution context is created, a lexical environment is created. Lexical environment is the local memory along with the lexical environment of its parent. Lexical as a term means in hierarchy or in sequence. 3. Having the reference of parent's lexical environment means, the child or the local function can access all the variables and functions defined in the memory space of its lexical parent. 4. The JS engine first searches for a variable in the current local memory space, if its not found here it searches for the variable in the lexical environment of its parent, and if its still not found, then it searches that variable in the subsequent lexical environments, and the sequence goes on until the variable is found in some lexical environment or the lexical environment becomes NULL. 5. The mechanism of searching variables in the subsequent lexical environments is known as Scope Chain. If a variable is not found anywhere, then we say that the variable is not present in the scope chain.

[@amit2197kumar]

Thanks 🙏

[@shikharverma1253]

brilliant

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good work!

[@SanketDeb]

well articulated bro !

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Great note , just love 💕 it

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It changes so much when the teacher is eager to speak about the topic and he smiles :) Thanks for that! Namaste

[@ashaykumar2427]

too true.

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I have 10+ years of IT experience, I worked on various technology, including JavaScript but I couldn't stop myself to post this as whenever I come to your video I find something new to learn. Thanks for all your hard work and sharing this to us.

[@akshaymarch7]

Next Video: let & const Hoisting and Temporal Dead Zone 🔥 - kzbin.info/www/bejne/eH-mZ6aijqida5I How was this video? Are you feeling excited? Let me know in the comments below. ❤️

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Great work

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Thank u so much ❤️🥰🥰🥰🥰

[@imnothing2infinite]

Started learning java script just loved the way, very clear, school children can learn from the way ur presentation, ❤️

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Thanks Akshay..for this initiative. It will help a lot of beginners like me. I hope you will be covering this keyword soon, I am bit confused with it. Waiting for the upcoming videos

[@dhanushikavlogs]

First of all thank you Akshay for such a good explanation of javascript. Many doubts clear after seeing your video. Can you please make a video on coercion in javascript. Regards, Krishan

[@HaykapSupays]

Thank you for doing this in English too, it makes it available to people from other countries, I am learning JS the proper way only thanks to you. Best regards all the way from Peru.

[@akshaymarch7]

Love from India ❤️

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@@akshaymarch7 Im from india too!

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Richard you are lucky you have found this man earlier, after watching his videos, I feel like I have wasted much more time on other js tutorials, I wish I found this guy before.

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@@danisnotdaning 🆒

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I am grateful to God...That I was able to find this channel❤😊

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Thank you, this comment means a lot to me. ❤️

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I second that 🙏🏻

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me too!!!

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me too

[@TheVideomate]

There is no other person I was able to find, who could explain all of this things better than You! Your content is amazing, covers all I was missing in my learning process. I am so excited!! No words to express how grateful I am!

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I am from Poland too. Cheers brother.

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Jonas Schemdtmann course on udemy.

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@@DeepuKumar-py5so how do you know? I also came here while learning from jonas Schemdtmann course. 👍

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x2

[@valp_co]

Saini is a good teacher. Though I think you need to read You Don't Know Javascript Yet Book Series by Kyle Simpson, then your head it'll get boom

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I used to be an average student in school and once when my elder brother taught me maths, I scored 98/100. You teach the same, like him. I feel so lucky to learn from your videos. Much love. ❤️❤️

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Love you, brother!

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@@Anand-zg6jv 150 rupaiya dega

[@arshradhanpura8663]

Akshay has no idea how much blessings he is getting, many people dont comment but on the behalf of them and also from me i would like to say a big Thank you.

[@shivangchaturvedi237]

After every video, I fall short of words for praising Akshay's work. Truly a masterclass series. I really hope KZbin pays him well for his content if it doesn't already.

[@farazk9729]

Akshay, a) You are an amazing teacher; skilled, articulate, passionate, and motivating. b) You are a wonderful human being for making this content accessible to all. God bless and namaste.

[@chandraroy8254]

This PlayList is my new Web Series... Looping over this again and again and again..... But in Every Iteration I'll something New.... You are Amazing Man!!!❤

[@AlysonLeonard-o9c]

what i love about this videos is that you really hammer in the terminology along with the concept. So many other people only define the concept once, rarely repeat the core terminology, and then ramble on about minuscule stuff. You said local scope, lexical environment, scope chain, and execution context like 1000 times... and now I will actually remember those words mean, thank you!!

[@aliramazani2024]

It's 12:03 AM right now as I'm watching this video. To be honest, I really enjoy watching you explain the concepts. The energy and enthusiasm are truly contagious. I just watched a long boring video on this topic and was ready to hit the bed, but your video keeps me awake to learn more.

[@unknown47896]

yes i totally agree with you😄😄

[@arpitaverma9607]

I am binge watching this "Namaste JavaScript" series.

[@arshradhanpura8663]

same

[@finjection]

I have been following you since you started your youtube journey. You are so relatable. I could see you were a little camera shy, learning how to interact with it,somehow trying to give content not readily available at other places. You changed my perception of looking at interviews, and seeing these videos now I feel you have evolved so much and I love the background music at the end. It brings a smile on my face and everything I just said flashes in my mind for a sec.

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True, the journey was amazing! And thank you so much for being a part of it along with me. ♥️

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You are just outstanding, I had total 15 years of experience but never seen such knowledgeable person. For me I was considering it as a rule of javascript but you just explain how and why it behave. Thanks you saved my lines of code. I am from old school so we used declare the variables in first line of block but inany case to make it even though we initialised we used to check for undefined. And such many blunders we do. I have not come accross such a in deapth knowledge person.

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You are making content that one can only find in books and even reading that will make no sense to most of us. Thanks a lot for creating videos like this ❤️

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Thank you for your beautiful words, Anmol. ♥️ Feels like the effort is worth it, highly motivated. 😇🔥

[@mahimakhandelwal5119]

I have not seen anybody explain Javascript with this much clarity and fun! These tricky concepts seem so easy now. That procrastination to take courses and learn things is not there anymore. I look forward to the next videos and have even started binging on to them. Thanks a lot for making this series. I love these quirks of JS now!!!

[@ujjawalchatterjee]

Brilliant Man, your way of teaching and expressions show how passionate you are for programming.

[@hardeepsiwach5104]

I agree with all your statements that first I hate JavaScript a lot I think that JS is more difficult than Java but after watching your videos I am falling in love with JavaScript I never thought that someone can even taught JavaScript in that great manner. Thanks a lot from me and from all the students and developers who are struggling with JavaScript. Love your videos Sir. Respect🤞

[@ajithingmire7782]

How on earth this can be free content. Can't thank you enough 🙂

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You made such a complicated JS topic seem so easy. Thank you for making us the see the beauty of JS. You are one gem of a teacher. Really grateful for your content.

[@universal4334]

Me in class: mam please explain it again please Akshay : please understad I I'll tell you again

[@akshaymarch7]

😅♥️

[@pankajpareek2730]

After start watching this playlist my love with JS is increased by 1000000000x . I have no words to express how grateful I am . (thanks a lot )*10000000000000

[@paritoshdadhich2954]

Hats off to your enthusiasm for making such deep knowledgeable content toward understanding JS more deeply. I understood all the concepts which you covered in this video like scope, Lexical environment, scope chain. Lexical environment path of the example which you covered in your amazing video. c() -> local memory of c + lexical environment of a() a() -> local memory of a + lexical environment of GEC GEC -> local memory of GEC + it's parent i.e. null Again thank you Akshay sir :)

[@akshaymarch7]

♥️✌🏼🔥

[@ridz4912]

I don't think I will ever forget what a 'lexical environment' is after watching this video. Some value bombs you are putting out man !

[@jessicavee6427]

I've been bashing my head against my desk so confused by scope and your 20 minute video cleared it all up and more. Top notch teaching.

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I just paid for a complete js course before I found this channel and I regret it. You FINALLY made me understand something I always hid from ... javascript. And no matter how much you avoid it by saying you work on Angular typescript, you cannot run away from js so I am happy I found this channel.

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This is one of the best courses I have seen so far. I am the type of person who likes to understand how something works under the hood and this course delivers perfectly. In only a couple of hours a got a very solid understanding of how JS works and it was as easy as pie. Can't wait to watch the rest. Thank you for these videos! ❤

[@funauntmimi2801]

This course should be a paid one. The content is awesome, easy, and clear. This is kind of as addictive as "FRIENDS" :-)

[@akshaymarch7]

Thank you Disha, it means a lot. ❤️

[@sachinrao7820]

Why you gave him this (paid) bullshit idea 😢

[@abhishekvishwakarma9045]

I got it -> scope chain is somewhat like DFS algorithm the difference is in SCOPE chain -> it is going to find the variable till it reaches the last parent lexical environment (if found in some parent's lexical then return from there) and in DFS it deep down from branch to branch (till child) until the element is found. Thank you for teaching multiple concepts😁😁🔥🔥👌

[@Anand-zg6jv]

Can anyone of u tell me the salary of a front end developer in a product base company like Microsoft ,Adobe ,LinkedIn

[@anuranroy4638]

Started watching this channel - switched from Brave to Chrome to let the ads play. Sir hats off to you that I will able to start with JS with full confidence.

[@varunkarthik6448]

The Lexical Chain looks like a node added in the front of a linked list, each time an Execution Context is created 👌👌Nice. I am enjoying this JS series

[@savysaurabh7509]

Bhai bhai, no words to describe this series. I was just writing JS code for the past year, and now I understand why and how it works. Thanks a lot for clearing the basics..

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I think I have achieved enlightenment today by watching this video. LOL. So damn good.

[@pranavtv9922]

First I would use a notepad to write down points from your video. I stopped it after watching two or three episodes. You are writing directly in to the heart. No need to rewrite on a notepad. Thank you very much akshay for this wonder full explanations. I had never seen a js tutorial like this before. This videos changed my perspective on javascript

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I am amazed by your teaching skill! I wish I found this earlier, at the same time, I feel that I am SO glad that I found this! It helps me to fill the gap in my head !!! Thank you so much to make these amazing tutorials even for free!

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when you say please let us revise shows that how much you want to contribute to a community and u want everyone to learn JavaScript hats off to you man

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You're the man! you are teaching like digging into our brains and putting the information with your hands! very good work, live long!👏👏👏

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Haha! I saw Akshay's videos a year back. Though my domain isn't web development anymore. I quickly wanted to revise them. And trust me when i say this it just took me 30 seconds to skim through this video and boom "NOW I KNOW WHAT THE CONCEPT IS"😂 Quality time spent on these videos in the past and now you just need to have a look. Everything is already stored in your brain. 😂

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Really addicted to theseee!🙌❤️❤️

[@siddharthbehra5250]

working in software industry for more than half decade, Now I understand what is lexical environment and scope chain and how it works, thank you Akshay, helps a lot

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The way you explain topics makes them look soo easy. Amazing content. Excited for future videos. 🙏

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ive tried to learn js for a while now was almost giving up but sir your video here makes it so easy to understand, i grasped everything,everything ...thankyou

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I thought I'll honestly never get these keywords, so much in depth and so beautifully explained, and most importantly everything begins from execution context. I mean I am actually repeating after you while watching the videos. I wanted to learn JavaScript for some job purpose, but after this video. I can completely say, I love it. I want to learn as much and I'm blessed I came across this wonderful series. Thankyou so much Sir 😍

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To be very honest this is the only one channel who teaches JavaScript in such an easy way. I can't say how much I love your js series. Cristal clear explanation.Please make other videos on js topics and react js 🙏🙏🙏

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Great video as usual. Whenever I see your video first I click like button and watch it.

[@akshaymarch7]

♥️

[@openworld7585]

Same

[@anjankumarmj01]

same here and it's worth more than that

[@karansinghnegi9384]

This guy is **legend**. I started watching his Js Series, and it's *perfectly splendid*. This guy is sharing his knowledge for free, Hats off to him. You the Best

[@0xFOXHOUND]

For revision Scope: where you can access the value of our function in our code Lexical environment : the Local memory(Created and goes hand-in-hand with 1st phase of corresponding execution context ) along with Lexical environment with the parent! and every time the lexical environment of the corresponding context is used, it references to its parent Lexical environment for simply understanding, I will try it as 'an onion example' see when one layer of onion(a variable) covers the layer inside it, it also covers the inner layers inside that layer and a point on our first layer of onion encloses inner layers our inner layer(variable and function inside the layer) gets covered by our first layer(can access the variable on the context) and the second layer(under first layer) encloses the third layer(innermost layer)still covered by 1st layer(can access the variable on layer) the Clojure concept starts here

[@analystakash]

TQ for the revised content

[@moumitadas1685]

Day by day I am gaining a lot of knowledge. thank you so much. previous days in every morning I think that how many things I have to read means I am pressuring to my self but now a days i will totally enjoyed to watching your videos and also fall in love with javascript

[@atif5752]

Akshay, you are a blessing man. An amazing, passionate mentor (not just teacher). Ps. where did you learn all these details?

[@akshaymarch7]

Checkout the latest Diwali Special QnA video. 😇

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If Ranveer Singh was teaching JS, this would be it! Wow what a style, keeps us binded from start to finish....and just when you feel doubtful about something, there is our brother reiterating already. I have never ended his single video with a doubt in mind.

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Call stack is beautiful ❤️, that intense explanation with full energy, really loved it 🔥 Akshay: how is the Josh? Me : HIGH SIR❤️

[@akshaymarch7]

🔥

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I come here for JavaScript interview questions preparation and completely fell in love with JavaScript and watching all your videos here, that's how you are making the videos on JavaScript. Thanks a lot.

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kids: that girl is beautiful bruh. akshay: call stack is beautiful! :>

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heheh :D

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Function is beautiful :)

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javascript is beautiful

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Although English is not your primary language, the way you explained those concepts is very polished, thank you very much.

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I felt like i had bought a premium course on javascript.

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I wish I had known this channel earlier! I procrastinated lately with learning JS fundamentals that I have never well covered. I was fed up with tutorials that made me so exhausted and overwhelmed while watching and trying to understand and remember these topics. This series is so different! I watch it as a cool Netflix series and I cannot wait for every new episode. I finally understand everything clearly! I have learned so much by having such fun! Thank you for providing such a valuable content!

[@rahultech77]

Explaining a concept is one level of skill. But showing how things run in the console is just exceptional. Never seen anything like it before. Glad I found this channel.

[@mansijoshijethava]

seriously..! God of the java script....three cheers for akshay sir... 🤩

[@ghostrAider98]

Just a note regarding scope chain for let and const: If let variable is declared normally without a block suppose inside a function, they will get lexically inherited to lower nested scopes, but if they are declared in a block, they are not available within the same function outside that block of-course but are not even inherited lexically in nested scopes. This means that the block memory scope is not part of the lexical scope chain. Try the below 2 functions and one can see the difference: function x() { let a = 10; function y() { console.log(a); } y(); } x(); //a will be available in the scope chain to be accessible function x() { {let a = 10;} function y() { console.log(a); } y(); } x(); //a won't be available in the scope chain and we get a referenceError

[@akshaybhatia7977]

Recently came across this JavaScript playlist and literally got addicted to this. Wonderfully explained and much thanks to creator for this.

[@sanjeevshrivastava]

To be honest.. this is the most practical and best video to understand Lexical environment and scope chain. Better than many paid courses. Good job Akshay!!

[@adarshchanewar4937]

bhaiya boht hi interactive way m batate ho yaar hats off, itna interactive teacher toh kabhi dekha hi ni, tum agar poore din bhi padha do na toh tumhara lecture poore din dekhle, koi bor ni hoga ,tumhari playlist m data structure dekh ra tha mila hi ni, bhaiya DSA bhi bata do aisa hi maja aa jayega

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I had to block you from linkedin cuz i thought you were another JS enthusiast with those "fancy" screenshots but darn was i wrong. BEST TUTORIAL EVER. Seriously one of the best. Thanks man and keep it up.

[@divyanshubhatnagar4601]

Mr. Saini, I can confidentally say this is one of the best JS series available on YT

[@madhuryadav2424]

I am just amazed how much this guy enjoys teaching, your videos never feel boring and i really enjoy learning along with you❤

[@gochallenge6146]

Man..!!! This is the bestesttttt video on lexical scoping. Thanks a lot! God bless you.

[@karansingh-nj7rs]

when person like me who is changing the domain can understand the concepts .. It means the Quality and Explanation is phenomenal. Keep up doing great work sir. I'm so inspired, now thinking to grow hairs like you... Namaste to all of you ... Happy Learning

[@bkarthini272]

Even after working as a professional for over 1.5 years, now only I got cleared in scope chain working. Thankyou so much @Akshay Saini. Keep inspiring us 👏👏and looking forward for more video courses😊

[@abhinavjain8962]

Even the Creators of Javascript didnt have this much of Understanding about Javascript..........Akshay saini sir. you rock.!

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bhai jabrdast hai ...bada darr lgta tha JS sun kar..you made my life easy to learn JS.. hoping other courses will also be Jabrdast ....Dil se thanks :)

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Hii sir you explain very deeply 😊 and it's very helpful plz provide more vdo on javascript

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IK there are a lot of comments here for you to read, but won't adding one will be really unfair. You are a gem, we need people like you in the education industry. You're killing it, literally. Super thanks to you for building up our js skills. Stay Blessed always ;)

[@GopalOswal]

youtube is blessed to have youtuber like akshay saini, aditya verma who are having awesome content keep the good work up guys

[@shreyaray5508]

After this episode i have more strong understanding for undefined and Not defined , can relate everything so easily now .......😎😎

[@aliakbaransaria3-925]

one of the best series of JS I found thanks to my friend who recommend me this channel

[@Hemanthkumar-pw7eg]

Your enthusiasm and eagerness in making people understand the concept is amazing,I admire you for that. Thanks for helping us understand the concept

[@VishalKumar-xl2xd]

Mechanical se hu aise Tashi hui pdi h IT m aake Ab todha confidence aa rha h Thanks bhaiya 💜🙏

[@AjayKumar-id7mb]

This guys is really teaching like a teacher who takes 5 min extra to explain the important concept. Love you Bro

[@abhishekporwal7969]

Aapse javascript pdke aesa lg rha he ki aapne hi javascript bnai he It's amazing to see great content like this in youtube. I believe that no one can explain javascript better that you.

[@iamsairash]

Thank you Akshay, What I learn in this video: Scope is where we can access any specific variable or function in our code. if there is some var b, where can I access the var b that is the scope of var b. When execution context is created Lexical Environment is also created. Lexical Environment is the local memory along with its parents' Lexical Environment. In every execution context, there's reference of parents' lexical environment. Basically, We get global execution context, and some functions in that global execution context and some more functions inside the functions. The inner functions can access variable of outer functions up to global execution context (hierarchical parent Lexical Environment). but the outer functions or global execution context can't access variables of insides functions.

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Feeling so blessed that via Linkedin, I was able to find out this course, Beautifully explained core concepts of js

[@marcusantenor793]

Danm, I don't know how I missed that video 2 years ago. Thanks bro.

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For the very first time, I am finding JS very interesting just because of this course. It is my web series too! Thank you so much for doing this :)

[@aj9706]

Best javascript series in the world 🌎🌎 💯❤️

[@S__Arslaan]

the example at 14:00, when function c() is called value of b that is 10 will be printed because it is contained inside the function a(), so its lexical parent is function a(). If you take function c() out of function a(), then function c() will not be able to access b as its lexical parent would be the Global Execution Context where b is not defined and hence output will show b is not defined.

[@amsemity1792]

Js engine creates Global Execution Context comprising of 2phases 1.Memory creation phase 2.code component phase Every execution context has its own lexicon environment that holds reference to its parent's lexicon environ Hence lexicon environ of an execution context= local memory space +lexicon environ of its parent Scope is where js can find required variable /function Scope chain is the process of find that req var/fn in the lexicon environs of all execution contexts Lexicon environ of global execution context is Global memory space +outer environ ie null Global memory space comprises of all variables and functions skimmed by js engine at top level even before the very first line code execution began

[@sanamahuja2033]

Scope in js is directly related to lexical env. Whenever an execution context is made lexical env is also created. Lexical env is local memory along with the lexical env of its parent. Lexical in terms means in order or heirarchy. C is lexically inside a. In memory part we also get lexical env of parent. Lexical env of global is null. When we move above in heirarchy of lexical env that is called scope chain

[@secretpanda7784]

Hours of reading and researching presented the best way possible. Much much appreciated Akshay.! Good Luck

[@AmoghC]

Aap tho coding baba nikale, 🙏 ithna aasan,ithna assan ho gaya ye concept aap sikane ke baad. Bohut pareshaan ho gaya tha mai iss concept ko leke. Thank you guru ji 🙏🙏🙏🙏🙏

[@pratikdevle5830]

Nobody can explain so easily and teach like you do. I really liked the way you show it in browser , never thought we can see this visually in the browser.

[@yaroslav8717]

I’ve never seen someone explains these profound JS topics on KZbin, thanks a lot!You’re very helpful! 🙏🏻

[@mercypill124]

i used to think that lexical environment is very tough topic but after seeing this video my mind changed about its difficulty....................thanku sir

[@DennisIvy]

Best explanation I've ever seen on this topic, absolute gold!!!

[@shrutikalamkar6167]

I cannot stop myself from commenting. This is something I needed from very long time. 💯Precious and Practical

[@jeet-smokey]

Love Guru of Javascript. Mujhe Javascript pasand nahi tha. Mausi ne kaha Akshay Saini ka videos dekh lo. Mene dekh li. Ab me pura din Javascript ke baare me sochta rehta hu. 😆 Hats off Bro for your efforts..!!🥰

[@rahulchauhan144]

First Ever Tutorial in which I never paused, He explains Really well Becoz he Knows it Very Well !!!