I just gave my interview and in this interview they asked me about closures. which ofcourse i have no idea. I have used it but no idea what is called. and i open my youtube and boom you are there. really like the simple explaination.
@@jessecalato4677 I know. Yes closures are used extensively but asking about the var gotcha in a loop is just stupid like who's gonna use var in 2024 for a new code?
@@Regeneration1996 of course in the end a hook will return some functions as objects and states too , when I was said react I mean most of it uses closures
I use one type closure all the time, combined with promises, when I have to execute a function on an array of data asynchronously, all you have to do is return a promise with a function, inside create a couter at 0, create the function thats going to process an entry, before return, incremente the counter, and excecute the inner function again, when its done, resolve the promise.
So, if I can sum up and get confirmation: a closure is where an outer function or scope is not garbage collected because there is an inner function that relies on the outer function or scope's variables... is this correct?
No because it's the same memory spot. In his example, when he does age = 30, it overwrites the value 29 in variable 'age', instead of creating a new variable.
Hello Kayal, In your second example for closuers "function elementCreator(element)", if we directly return document.createElement(element) instead returning a function then what difference will it make, I think direct return will be better, what you suggest.
Great video as usual. But Kyle, your 1x Playback speed feels like 1.25x bro. 🙂 Interviewers also ask that how you will print 0,1,2 when using var i=0; . We have to use the concept of closure here.
Thank you for this video and the job you do, but what is a JavaScript Developer? The only thing i could find is "JS developer" - in react, angular, vue and stuff Is there atually a job for JS developer in JS?
I was just wondering, is it possible to see the what structures&code JavaScript actually creates? Don't know how to call it. In C#, you can see the different stages ( C#, IL, ASM ) and that makes perfectly clear how closures technically work.
I honestly thought that it didn't call function too until it said return function to and since the variable was already age 30, that is why it started with 30. What if you called the function first?
I had doubts for this last example, so I asked gpt to explain it to me deeply. It errored the first few times but at last gave the correct answer which claude also verified. Yes, for each iteration of the loop, a new scope is created, and within that scope, a new binding for the variable i is created. Here’s a detailed breakdown: First Iteration (i = 0): A new scope is created. A new binding for i is created and initialized to 0. The setTimeout callback captures this binding, so it logs 0. Second Iteration (i = 1): A new scope is created. A new binding for i is created and initialized to 1. The setTimeout callback captures this binding, so it logs 1. Third Iteration (i = 2): A new scope is created. A new binding for i is created and initialized to 2. The setTimeout callback captures this binding, so it logs 2. In each iteration, the let declaration ensures that i is re-declared and re-initialized within the new scope. This results in three separate bindings for i, each one unique to its iteration.
Do you know how to do that integer story with a public bank website inside a private login inside page two with a currency and interger value where I need to insert a legal agreement account balance update from 0 => R 1 000 000 Zar ? It’s a public https web address?! The javascript wipes the direct insert after page refresh how do I make the interger value const? Do you have team viewer and want to try and or show me?
Hate to break it to you, but absolutely no one is going to help you with manipulating a bank website. Further, what you're seeing isn't just javascript wiping the value. It's retrieving the value from the bank's servers, which you cannot modify no matter how much you manipulate the page. Gotta study up a lot more and stop asking for advice on malicious activities on RU-vid. Also, on the off chance you do manage to do something malicious, you will almost certainly get caught.
@@JacobZigenis my laptops storage is full and not booting at the moment so I cannot screenshare. I don't see how it's my problem the external and Internal banking staff cannot manually show me howto insert credits into bank tables in cobol or whatever the language is from the email pseudocode to the browser web security layers in the osi model so that I may make debits to pay attorney legal fees for bank account topups. I think it's worth a trial investigation ie look, screenshare, record discuss, etc and a look into the file and code framework on the Javascript and in the console just for a deeper explination, because I just know sql server, table updates, hidden servers, html, Javascript and css. The actual coding language and topology to see exactly where the update changes are made. Worse case the system gets reported and then gets fixed. I don't think it's too complicated less than 1000 lines of code plus minus with like 400 lines on my screen at once with like 30 lines each side of the zero balance variable.
<a href="#" class="seekto" data-time="300">5:00</a> nope u didn't called your function on that line, u declared it ; u called it on the last line : return func2
A class is syntactic sugar for a function, not necessarily a closure. A function becomes a closure when capturing variables from the parent scope, not because it’s a class.
They are kinda the same thing. Higher order functions return a function and usually, the function that is returned has access to variables inside the original function which is what closures is. So yeah different concepts but essentially the same thing
If you have a global function that captures a variable from the outer (global) scope, then this function is a closure, because a closure is a function that captures variables from the parent scope. Even if you are calling console.log, because console is a variable in the global scope, you are capturing a variable and therefore your function is a closure. The only functions in JavaScript that are not closures are pure functions. Please do some research before making a 13min video about a topic.
If you work with React you desperately need to understand closures. I have run into some insane React bugs that were created because of closures in complex functional React.
