Intermediate React.js Coding Interview (ft. Clément Mihailescu)
Ғылым және технология
I give Clément an intermediate level React.js coding interview where I test his knowledge in creating a table that can sort columns and search for values.
Code: codesandbox.io/s/quizzical-th...
Checkout the interview I did on Clément's channel: • Medium Google Coding I...
Previous beginner React.js interview: • Beginner React.js Codi...
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Пікірлер: 471
Checkout the video we made on Clément's channel where I do an intermediate Algo interview: kzread.info/dash/bejne/ZqiN0bixYLTVfpM.html
@alhajee
Жыл бұрын
That smile on your face at 13:00 seeing Clement over-engineer. Simply maping the values would have solved the problem
Fun fact, Ben was too lazy to do it so he made this interview up so Clement finish it for him
@ManavKaushal
3 жыл бұрын
more like a plot twist
@TheoParis
2 жыл бұрын
@@ManavKaushal LOL yes
@RohitKumar-ly6pb
2 жыл бұрын
😂😂
@divyanshusah2809
2 жыл бұрын
🤣🤣F
This intermediate React interview was fun, but now I wonder… How fun would a *hard* React interview be? 👀
@neethology
3 жыл бұрын
Good question, no sweat for you.
@Yassinebridii
3 жыл бұрын
An advanced coding Interview would be cool to see too.
@robinsu3796
3 жыл бұрын
I think it’s time for redux then
@ryanspivey1819
3 жыл бұрын
bro you need to shave
@tkdevlop
3 жыл бұрын
Implement react Reconciliation In 45 mins
Ben: can you flatten this simple object? Clément: sure here is a recursive linear time complexity algorithm to flatten every possible object in the world
@aurorapaisley7453
Жыл бұрын
How to flatten
@thebonvoyageduo
Жыл бұрын
my thoughts exactly 😆
@negasonicteenagewarhead
10 ай бұрын
But it's easy?
I have never seen someone over engineering a simple task like that. Respect!
@samgord4669
2 жыл бұрын
this is the comment i was looking for. #respect
@brothercaleb
2 жыл бұрын
😂
@qreamybean
2 жыл бұрын
I came looking for this comment. I was in awe the entire time! haha
@slolom001
2 жыл бұрын
Yeah I was thinking the same thing. Wtf?? Was there a point to that?
@Jindujun
2 жыл бұрын
yeah, I was shaking my head sometimes but I guess thats how amazing minds work xD
Ben, your smug smile during the interview would simply make me shit myself thinking I was always wrong.
@RohitKumar-ly6pb
2 жыл бұрын
😂😂😂
@monome3038
2 жыл бұрын
agree xD
@kiranpillai876
2 жыл бұрын
I died laughing every time Ben did that
We started with a table, now we have an AbstractTableHeaderGeneratorFactory
@inordirection_
2 жыл бұрын
lmao
The title should be "Dynamically flattening objects in javascript with Ex-Googler - Clément Mihailescu " XD
@sammusaev5883
3 жыл бұрын
"Babe, it's 4pm. Time for your dynamic object flattening. "
@smoothbeak
3 жыл бұрын
That dude worked at Google :P?
@xit
3 жыл бұрын
@@smoothbeak Yeah! No Cap XD
@webdevinterviewtrainingusa1494
3 жыл бұрын
kzread.info/dash/bejne/qoB73JaqhcKWkqQ.html
@Avoidlol
Жыл бұрын
lmao, so true. never heard the word "flattened" so many times in 30 minutes
Man i was like shit they think so fast... then I realized i watch yt on x2
@shamimahmedrian4222
3 жыл бұрын
This is hilarious
@satyasrikar709
3 жыл бұрын
this is so funny xD
@vinayvarma266
2 жыл бұрын
Same with typing speed
@splasher2119
2 жыл бұрын
It's hard to believe that you were watching on 2x and never noticed 😕 maybe say something more realistic next time
@unarei
2 жыл бұрын
@@splasher2119 I watch everything on 2x so I don't notice it usually
I love watching people way smarter than me struggling with things that are fairly simple to me!
@timm8998
6 ай бұрын
How do you know he is smarter?
@MyKneeHurts
2 ай бұрын
maybe because he is at an advanced level of programming within just a couple of years of starting, along with the fact that he did math at uPenn. idk tho@@timm8998
@sabukuna
Ай бұрын
@@timm8998 i guess the way he over-engineered it
Look at how happy Ben is when there's not a graph matrix involved
me: I know React, Vue, Svelte and SEO best practices. my interviewer: good. please solve riemann hypothesis with the least space & time complexity. I will give you 10 minutes to solve. good luck.
@cryptonative
2 жыл бұрын
lucky they didn’t ask to center a div
@gountaa
2 жыл бұрын
@@cryptonative #myUglyDiv{ left : calc( 50% - somebullshit value that makes my div looks almost centered); }
@TheoParis
2 жыл бұрын
@@gountaa i just use flexbox
@paucolome4298
2 жыл бұрын
@@gountaa bruh
@gountaa
2 жыл бұрын
@@paucolome4298 It's best practice trust me i read it on a 14 years old stack overflow post
I am grateful that I got Clement's video recommended, these kind of videos does it job when you are not too deep in some stuff. Like in this scenario, frameworks. I've understood a lot about React with these two videos (and also the long video that wrapped all React hooks tutorials)
Watching him flatten the object really made my head hurt
@kadensharpin2156
3 жыл бұрын
It was unnecessarily over complicated
@thesupercoach
3 жыл бұрын
@@kadensharpin2156 Agreed. He read too much into it, got told he read too much into it and decided to keep going anyway.
@Aurora99aroruA
3 жыл бұрын
Yeah that got overcomplicated by simultaneously introducing dynamically generating the keys / table headers, which is kind of unrelated other than it becoming more complex in a context of flattening. It is a requirement by itself with pros and cons, the latter being that your table will look different depending on your input (first input in this case). There was no requirement for this at all as I understood the assignment.
@wizard_of_az
2 жыл бұрын
He had overcommitted to his intuition while missing the que from the interviewer to simplify the solution. So fun to come across this while working...
@hstandeffer
2 жыл бұрын
I’m sure being around algo based problems all day makes you think the simplest approach is never right when in this case it obviously was
I loved the fun vibe around this coding session ;) looking forward for part 3 - hard mode
All this dynamic flattening might be neat in other use cases, but since this is TS, and a presumably well-defined API response that doesn't have too many fields, creating an interface and working with defined object keys would be so much easier IMO. Specifying an interface (or multiple) for the API response would have been my first step actually.
@jkho8365
3 жыл бұрын
What's ur thought on .then vs await?
@danshilm
3 жыл бұрын
@@jkho8365 I default to using await and only use .then if I have a good reason to.
@jkho8365
3 жыл бұрын
@@danshilm same I use await too. Seeing Clement do it and not sure if there's a good reason too tho
@danshilm
3 жыл бұрын
@@jkho8365 the 2 are almost identical in the way they work, in performance and the only big difference I've found is when handling errors. There's a long article about it on the v8 blog if you want to read about the technical details of this - this is the relevant section: v8.dev/blog/fast-async#await-under-the-hood
@jkho8365
3 жыл бұрын
@@danshilm thanks
53:01 *Ben bursting out laughing* "Do you have prod code that does this?? 😂"
Loved this one , this kind of content is what differentiates Ben from other content creators. Loved the coding exercise, it was interesting
36:28 sort function: works first try Ben, knowing the pains of javascript development: "beautiful"
I was waiting for it from a while.. thanks, ben💕
TIL the Clement full text search. Thank you Clement I like it! Astig!
I loved the way this guy implemented recursion effortlessly. I keep struggling a lot with recursion at times... Also I realized I was watching it at 2x speed.
18:40 Ben: what have I got my self into
I recently had to implement this kind of table where the table had bunch of row & colum level actions and a annoying nested object to deal with and I can feel Clement here! And to increase the complexity the table was live that is it was continuously getting updates from a live feed and to implement sort, filter to that etc. Was another ball game.
It’s crazy I literally had to do this this week for my react internship! Wow I’m an intermediate now
@kokokok7171
2 жыл бұрын
Not like you can come up with all this from just your mind
I completed a full stack boot camp with js/react/node. It began 9/19, but ended 3/20 right as pandemic started. Knew I wasn’t going to find a job right away so went right into a data science boot camp that promised a job as long as you finish. Got a job as an analyst and hardly even doing any programming now, just a little Python on the side. Originally got into it because I loved learning to code and now getting back into the dev side. I personally love JS and React so much more than Python. I have used a little Flask, but React just seems more enjoyable to me. These videos are helpful to get me ready to search for a role that allows me to use both skill sets. Thx
What a trip down memory lane! I had just started learning React when I saw the previous interview. I'm still learning, but ik all the things done in this video
@saikumar880120
2 жыл бұрын
Any tips on learning react? good website to study? approach? and all that
Unbelievably useful video for me. Thank you both!
pro tip: using the index as the key attribute is an anti pattern. Use something unique to the item instead (and make sure it’s a primitive type)
@jimmyliao6429
2 жыл бұрын
Yes, especially you have sorting feature.
@joecamroberon9322
2 жыл бұрын
Yea I remember reading about this recently. It worsens performance because it messes with React’s reconciliation process. When you have indices for a key and you move elements around, React loses track of what was updated/added/removed due to the same key switching nodes. I think this is how it happened at least
@akj3344
2 жыл бұрын
@@joecamroberon9322 correct.
@kevinbatdorf
Жыл бұрын
@Sebastian Voráč be careful with that too because it will bust the cache if sorting happens, making your app less performant.
Ben is one of the only youtubers that I don’t have any second thoughts about watching videos longer than 30 mins
Nice interview, love to watch more intermediate interviews.💓
Damn this stringify moment was hilarious! Great creativity, love the interview
Just came from the beginner React coding interview with Clement. Again, this was super informative and helpful. A bit let down you didn't make Clement add authentication like you said you would in the previous video but its all good haha. Awesome vid!
Question for Ben and Clément! Can y’all each make a video for best practices in React in front end and best practices in Python for algorithms?
One hour coding without looking anything up on the web or pasting something from stackoverflow? Cudos!
Watching Ben watch Clem over engineer is better than any comedy show I've ever seen.
I love the way you code!
I feel good knowing that few years ago I didn't even know what DOM is and now I can easily do all of these things!
Wow, Clememént struggled with the flat obj stuf man
Watched 1st part when I am beginner😅 in react now I am working in a company as a full stack it's been so long 😆
@DaJukes
3 жыл бұрын
working in india?
@sur_shrimpster
3 жыл бұрын
@@DaJukes why does it matter? smh 😑
@ahmadmuslih
3 жыл бұрын
@@sur_shrimpster bruh chill he just asked
@karthik_sama
3 жыл бұрын
Where do u work bro?
@Vilhena6969
3 жыл бұрын
me too :D
Haha watching this fresh off of the intermediate Algo Interview on Clement's channel. Tons of fun and I hope you guys can take a shot on a 'Hard' mode sometime!
Kudos to Clement for putting himself on the spot. 👏🏽👏🏽👏🏽👏🏽
This is amazing, do more of this :D
I was just building a little react app which has a couple table-based displays, was thinking of adding column based sorting and a search function so this is great. Now I just need to get Clem to do a mock interview with me
I like how both of them interview each other
Learning so much, thanks for good contents 👌
It helped a lot. I was nervous about how much I know. At least now I don't doubt myself.
I always tend to store the transformed data for display in component state, since that state is tied to the UI. This gives you a single source of truth, easier to maintain, and makes debugging much easier, since the state reflects exactly what will be displayed. And as you may have noticed in the video, you can avoid having to change any UI output in some cases-like adding a sorting functionality. If I use global state management, I tend to also store the transformed data there, except if a component does something special with the data that is not compatible with other components that share that same state.
I'm only 8 minutes in, but I have to say this is a really wonderful video, and helpful for those getting in to the industry. In addition I also appreciate the high resolution video, that just makes it that little more enjoyable and easier to follow.
Its was great to see, keep it up!!
Most of the people won’t be able to do this much given the same amount of time, so definitely impressive there. One thing I think would be helpful for the viewers is to explain different ways to structure the code so that the code is more maintainable and performant :)
so glad i watched all the way, watching ben laugh at JSON.stringify is priceless
@marcusaureliusregulus2833
2 жыл бұрын
Lol. Is it slow? Or why did he laugh so much😂
Clement is an algo and interviews hero. But I would never let him write production React code :D
@JohnDoeX1966
2 жыл бұрын
Why not? He seems smart to me
@tiejeevan
2 жыл бұрын
Fuck that, it's 3 line code. Instead he wrote 30 freaking lines
@Jindujun
2 жыл бұрын
@@JohnDoeX1966 because he overcomplicates simple problems.
@JohnDoeX1966
2 жыл бұрын
Jindujun oh okay
@mayankjha7444
2 жыл бұрын
@@tiejeevan but he thought and countered on the fly.
I totally respect that this is all on-the-spot (which makes it great to watch but not suitable for educating beginners), so it's a bit unfair to judge you from the armchair, but some remarks anyway. The flattening vs dynamic has been mentioned, but the sorting function sorting on what the sort order will (presumably) become later on, is unnecessary coupling (just reorder the lines so that newSortingDirections is determined before sortData) . Reversing the sort could also be done by switching a and b at the start, or multiplying the result by -1 for reverse. I 'feel' there's a bit much intermediate variable creation to my taste, but Code Complete would probably approve :)
superb timing.....thanks for this
Need more like this ben
U could store 1 or -1 as sorting direction and multiply them with -1 to get the appropriate return values sortingDirection = 1 if a if a > b, return sortingDirection if a = b, return 0
Stackoverflow: flat array js Copy, paste Continue Less than 1 minute 🤯
This is great. Can we do like 50 more of these?
This is great interview. I have an interview on thursday for fullstack position. Hope it goes well🙏🙏
Interviews are fun. I’m eighteen and will soon will be questioned. Watching you guys helps me to cool down a bit, but I still fear to get negative experience from one. Thank you.
I was an Angular developer when I watched the first part. I moved to react recently.😅
been waiting for thissssss
This is gonna be top notch content
damn that curly brace smash of JSON.stringify was cold. Thanks to both for the video, it kinda went off track (to me) in the first part with the overengineering but can't complain!
this has to be a good example of over-engineering failing you an interview. not only was it severely over-engineered, it also wasn't really a good solution. why would you ever want to get data from an API and dynamically display everything it returns? you have no control over what you display. either way, cool vid ;>
18:41 Ben be like "What the heck, Clement XD"
ok so, i just wanna share my react interview experience for a job i did not get. i've been working with react on and off in the past 3 years. i watched these two videos to see if i'm ok or not and both of these videos were too easy for me. i also passed the first assigned coding challenge the company gave me, it was nothing but fetching, rendering and filtering data based on an input field and writing some tests for it. but the reason i failed the interview and did not get the job was the following questions that i couldn't answer properly : 1- what is virtual dom and what are the benefits of it? 2- how to test an endpoint on the front end ? 3- we know we should update the state in an immutable way, but why? what happens if we don't ? 4- what is the event loop? 5- what are pure functions? ---- there were other questions that i answered like about closures or higher order components. but the 5 above took me down. honestly i'm a little mad about the 1st and 4th question, because i don't really understand how knowing the answer to them makes me a better dev. but anyways... make sure you know the answer to these. happy coding!
@cosmin4437
2 жыл бұрын
Do you know the answers now for 2, 3 and 5? 😇
I guess Ben had a 10 line code solution for this. Thats why Front End could be so hard and easy at the same time!
Ben's subtle smirks make it so funny. Wayyyy too much for that simple task lol
Have been waiting for this...
awesome showdown!!
possible titles: "why you are ready for FAANG but you don't know yet", "exposing youtube coders"
I love how both of them couldn't get that smirk off their face... especially clement
Thanks guys, I have been failing at interviews, I have got redirection.
I forgot that you can have helper functions *outside* of your React.FC... I've always had them on the inside of the React.FC, but that's inefficient because every instance of the component has to create that callback function upon every render (maybe helped with useCallback), but storing the callbacks outside of the component won't require any duplication. (Like how pre-ES6 classes, we were supposed to add functions to a "class"'s prototype instead of storing the function directly in the class, to reduce duplication)
I thought ben is introducing clement , when youtube showed me algoexpert's ad 😁
the way he casually dropped a recursion solution.. sheeeesh
They back!!
🤣🤣ben bhai you are bohot hard🔥🙏
This is more a JS interview than a ReactJS. Only the first question was really about React.
I don't really know react but I loved watching this
Ben looks like he’s finally seen some sun! ☀️
This was super helpful. Thanks a lot
My guy made a recursive object flattening linear complexity algorithm in a react codebase. Insane.
One should never use personIdx as a key. If the length of data changes, react would re-render the existing entries as well. A separate property like id should be used which is unique and consistent.
This is great! But you should probably caveat (make it really obvious) that here you're not following best practices, and are just writing quick code to get something working - just in case newer devs think this is a great example to release to prod!
U can stringify the array object to so that u can access a normal array
Well now I feel more confident in my skills, having it done in a fraction of the time hahaha
@Avoidlol
Жыл бұрын
the point of an interview like this is not for you to do it as fast as possible, it's to show off the way you approach problems and the way you think. any beginner can do these tasks obviously
just beautiful
What is this application that you guys are on that lets you both code on the same document??
Around 7:30, what was the Person: any about? I’ve never seen that sort of problem.
Ben almost laughing the whole time has me dying
genuine question - wasn't it easier to destructure person object in map? ie apiPeople.map(({ location: { street: { name: streetName } } }) => // print stuff) ?
@pe....
3 жыл бұрын
Yes my boy, it was.
@wizard_of_az
2 жыл бұрын
But he had to dynamically do it... Lol
@MaximoJoshua
2 жыл бұрын
that's what I thought too, its so simple to just create an array which maps all the values and sorts it, I don't know why he created all those functions, and random state stuff...he used Object.keys so many times, when he could have just used Object.entries and gotten it all at the same time ....
I just wanted to ask that .... you linked a sortingDirection to every column... but when i was doing this task i had a different idea... i just stored the column we are working on in a state like "previousSortingColumn" ... that way if we are moving onto new column we can just compare to the "previousSortingColumn" if its true then reverse the array if its not then just sort into the ascending order... what i wanted to ask that is there a catch in my way of doing Clément
Does anyone know if it’s required to use return in the fetchData function? Doesn’t it return a promise anyway?
I like how Ben is gone when the console.log appears
Bro, Clement is a monster. Regular devs would've used reduce, but watching his approach blew my freaking mind.
@dadestor
2 жыл бұрын
His approach is overly complicated and terrible
@bonfacenjuguna214
Жыл бұрын
Over engineering mostly
that json.stringify made my day 😂
These variable names are killing me.