React Interview Questions 2020 (7 Questions)

In this video I break down 7 react interview questions I would ask candidates now in 2020 to see if they have the react chops!
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refs video: • React Refs Explained w...
react interview questions part 2: • React Interview Questi...

Here is my humble contribution: 0:40 - Unidirectional Data Flow 3:05 - Props x State 4:53 - Lift State Up 7:05 - Controlled x Uncontrolled 9:46 - Refs 12:21 - Importance of Keys 17:58 - Context For whoever is reading it: You have gotten so far! You are gonna get the job just believe in yourself! 😊

[@soumyadippandit4810]

I have an interview today. Your comment really helped. Thank you.

[@nimamc]

This is a great video! No non-sense. I'm a pretty experienced React developer and I can confirm that these are actually things that you're going to need in your work.

[@andycao]

I alway watch this kind of video by using 1.25x. but this time I need to a little bit slow it down. Anyway, thanks for sharing these knowledge.

[@yogevstrauber8657]

same here! sometimes I use even use 1.75 but this video I used 0.75 lol. I'm glad I not the only one

[@CBMaster2]

lmao n00b me i used 2.5x

[@brianpato]

Can confirm

[@thedeziner]

Same here

[@ToddDunning]

One of the best React tutorials out there, and I've struggled with 'em all.

[@kckunal2612]

I am so glad I discovered your channel - thanks for doing such an amazing job explaining everything with so much detail !

[@nbharucha12]

I agree with others, you've explained things very nicely. I've been using react for a few years and not using the index as a key is important but I've never really dug deeper into it. The way you've explained it, with an example, really clicked! Keep it up!

[@nachmanfriedman7821]

Fantastic video, I use React every day and your explanations were so good that even I learned something new! Keep up the good work!

[@CodingWithChaim]

Thank you so much! I appreciate the feedback!

[@DesignDensity]

Fantastic set of questions, one thing worth mentioning in relation to Q1 is that it is also referred to as "1 Way" and "2 Way" data bindings, as per the given example, React is 1 way data-binding and Vue is 2 way data-binding. Thanks for sharing

[@mokroargra7277]

This was great ive been learning a lot of react past 6 months and you cleared up a lot. Thanks!

[@CodingWithChaim]

My pleasure! I’m glad you find it useful

[@bearrorist5658]

This was extremely helpful in reaffirming my React knowledge. I've been using it for a while in personal projects and I just found out my company is looking for a React developer. Brushing up in hopes of landing the promotion! Thanks for the video!

[@ruinnn4104]

Thanks Chaim! Looking forward to your future content

[@19boro76]

Excellent video!!! I am learning React JS and I have found the video very informative, especially when you go over the snippets and explain them thoroughly. Great job, thumbs up 👍

[@samuelpai9601]

great video Chaim, learned so much!!!

[@cesarherrera9690]

One of the best videos I've seen and I've been already a month preparing for interviews after 6 years of working with React already, but now I want to change to work another place

[@ganeshbirajdar4382]

Thank you so much. The info was clear and precise and it helped me clear some misconceptions too ! Great work!

[@Sarah-rc8dl]

You really give great explanations on crucial topics of react. Thank you!

[@uicornerwithJ]

I really liked your explanation about using n.id instead of index in key attributes. Amazing stuff.

[@commondev2595]

I am sure every viewer will learn something valuable from this video. Looking forward to more content.

[@sumanas6993]

Liked the detailed explanation. Really helpful. Specifically key and context. It gave me clear idea

[@Mustafa-taheri]

every answer with a code snippet... tats what makes this video amazing and a lot easier to understand... ThanQ.. Happy Coding..

[@MrTedane]

I've learned more in 12 minutes than all the hours I've spent o tutorials. Thank you so much definitely got a new subscriber

[@CodingWithChaim]

Happy to help

[@Mr8000D]

This guy knows his stuff. I really enjoyed the video!

[@CodingWithChaim]

Thanks! Glad you enjoyed the vid

[@miguelencarnacion9278]

Excelent content and you know how to explain it clearly. Great video!

[@sanjeevsinha-in]

its kind of learning entire core react concept in minimum time possible. Great content.

[@ForevernitchProject]

You helped me get my current job, every question you mentioned was brought up and I was able to elaborate, you made the concepts make sense to me. I cannot thank you enough. I’m now a lead dev for a new project, loving my job!

[@CodingWithChaim]

Wow!! Congrats! So glad my videos helped. Appreciate the comment

[@maximstolovich2163]

Awesome content and up to date. Love it!

[@CodingWithChaim]

Thanks!

[@danishdk7399]

Best video I have found so far, helped me getting prepared for my interview so well.

[@CodingWithChaim]

Glad it helped!

[@devanshishah9481]

This video is so detailed and very nicely explained. Thank you!

[@chennurumanu]

Fantastic video with basics at one place

[@mdmoinmoin8888]

Man you are special my brain had to be 💯 focused and not even for a single second I got bored.

[@Alexgub84]

Thanks for the great examples, I learned a lot! Going to your next video :)

[@jamesjefferson163]

Great content. Clear and concise explanation and examples. Well done.

[@theoryofdeadman482]

Wow , your the 1st one i didnt have to speed up to 1.5x . Good video!

[@jasonwhittaker3940]

I never fully grasped the difference between controlled vs uncontrolled component, but you explained in two minutes what seemed obvious and other documentation I couldn't.

[@aaronomale3930]

You're a great teacher. I'm learning react and couldn't grasp certain concepts until now. Do you have a react bootcamp?

[@clockwerkz]

Love this video. A lot of my React learning has come from Udemy there's so much of this that I've learned how to do, but never really understood the "why."

[@CodingWithChaim]

really glad you found this video helpful!

[@harishg9429]

great explanation, never really had understood unidirectional data flow in react, you made it easy. Thanks

[@GarrettVan]

This is very helpful interview prep. Thank you!

[@CodingWithChaim]

Glad you found it helpful

[@petroniemkov6516]

one of the best teachers I ever seen

[@johnbaltes7518]

Great video, solid explanation on prop drilling and useContext.

[@muhammadjawadurrahim4883]

Great Content !!! Thank you ..Hope to see more videos like these

[@Iallisios]

fantastic video. Thorough explanation and a good choice of questions :) Thank you

[@CodingWithChaim]

My pleasure! Very glad you’ve found it helpful

[@UrbanBDKNY]

Love the part about keys. Now I understand why. I knew it was not good for performance but didn’t know why

[@omancoding5687]

This is really video, the concepts are made clear. Thanks Chaim. Love from Oman.

[@CodingWithChaim]

You are most welcome

[@zaremakayasova8097]

Thank your for this amazing React tutorial!

[@CodingWithChaim]

Want some help with an upcoming React interview? Follow this link to book a 1 on 1 session with me! www.codingwithchaim.dev/

[@cristianjuarez1086]

Hello, i am new and im not sure about seniority levels yet, i wanted to know if you are considered Ssr or Sr or Jr, i would appreciate a reference, thx!

[@emmanuelonwuka7664]

Sir, this should be my first ever comment on KZbin and I just want to say that I totally loved this video. I wish I could leave 10 likes all at once. Thank youuuuuuu

[@JimmyCheng]

You're probably the smartest instructor I've ever seen. Everything you say is to the point. One suggestion thought, maybe consider making the pacing a bit slower :)

[@jagrutipatel5256]

Very easy to understand with examples. Thank you

[@parhamkhamsepour7633]

This was so helpful. Thanks. do you have a video explaining Hooks and why they are useful and why are they needed?

[@reymarkandog1441]

Thanks, good sir. I've learned a lot from this one video.

[@adnantariq3346]

This guys is awesome in his explanation

[@ArifUlIslam-vl2kj]

this guy deserves a medal

[@tapastrivedi8088]

It's crazy how many of these questions I was asked in a recent interview, and I couldn't give convincing answers. If only I had gone through these 14 questions before. Great vid nonetheless, and I found the JS playlist equally helpful. Thanks again!

[@CodingWithChaim]

Hopefully this helps you ace your next interview

[@pouriakalantari6537]

Very insightful and full content 👌 👏

[@violetaveleva6143]

Great questions and excellent explanation! Thanks for sharing

[@CodingWithChaim]

Really glad you enjoyed!

[@amirrahnama8104]

Super insightful!

[@Scottni2]

This....is.....Amazing. SUBSCRIBED

[@irynah2659]

Great video and explanation, thanks!

[@CodingWithChaim]

Glad it was helpful!

[@e_tas_]

I have my first front end technical interview and the material from this video was exactly what I needed, thanks

[@mz6958]

how did it go?

[@e_tas_]

@@mz6958 The recruiter made a mistake and said the role required a bachelor's in Computer Science. I got a job elsewhere though and I learned a shit ton already. But then it moved to part time because it is an early stage startup that lost funding, so now I'm considering updating my resume because I'm only gonna be working 10 hours a week at this job.

[@mz6958]

@@e_tas_ Damn, that sounds like a rollercoaster. I guess if you will only be working 10 hours a week you'll have a lot of time for applying to new jobs though, right? Wish you the best of luck with it! I have my technical interview on Wednesday

[@e_tas_]

@@mz6958 Yeah hopefully it won't be too much of an issue since I have about half a year of work experience

[@Adam-nw1vy]

You have a talent for explaining things! Keep doing this. I have a question: what level are these questions? Say I'm someone with almost 2 years of experience. Is this what I should expect or this is something that a more junior/entry level dev would be asked?

[@sunilthind3257]

Thanks for this wonderful video.

[@iliketocode6986]

you make me smarter thank you. My react iq increases with every video thank you.

[@CodingWithChaim]

You are very welcome! Glad you’re finding the videos helpful

[@BobbyBundlez]

great. i have trouble articulating this stuff but know answers for most part. this really helped me with my soft skills!

[@CodingWithChaim]

Try writing the answers to these questions. Might help you articulate more clearly

[@BobbyBundlez]

@@CodingWithChaim just did exactly that! i took a course with stephen girder on udemy and he covered sooo much of this stuff (really great course and extensive) but hearing it all rephrased through your words makes it easier to form my own way of phrasing this all now as well! loved your explanation of unidirectional and the reconciliation model... never heard of that before!

[@huseynfy]

Very useful content! thanks!

[@AIShorts119]

thanks for the phenomenal video. cheers

[@inordirection_]

Sweet, I finally get why keys are important, and I'll stop with the key={i} just to quiet warnings

[@CodingWithChaim]

Not in all cases is it bad. This really is only an issue with a data set where the order of items can change, like for example if you delete an item. In a case where you simply render the list, index is ok

[@paoro814]

wow you seem to be really an expert at React

[@ElectricBlanket1122]

Loved it!

[@dukewellington5222]

Did I miss something here? What actually happens when a user types something into the input field of the uncontrolled component and then hits the button, that this component has? Otherwhise..great content, really gives me some insight!

[@jamesdong8932]

Great video, detailed explanation of everything, easy to understand. Just have to slow it down to 0.75x

[@CodingWithChaim]

Thank you!

[@anubhapant5227]

It's an amazing interview tutorial.

[@asifahmed6568]

Pure Gold 😍

[@comod]

Leaved a like to watch/understand later

[@fullstackprojects5615]

'Lifting State Up' question : You didn't mention the main point that I think is the core to the answer to that question - When we lift the state up then we call a method in the child component that in turns calls the reference to a function that was passed as a prop to the child from the parent component. This is done in order to update the state in the parent component because updating the state of parent component cannot directly done in child component. In this way we kind of lift the state up from child component to parent component which ensures that parent is aware of the fact that child is requesting the state to be changed potentially because child relies on the updated value of that state. I am not able to understand your point for this particular question in the video. Could you please explain?

[@aadil4236]

Do you necessarily have to use "refs" to get the underlying DOM element, can't you use document.querySelector() for that. I am new to react. Would love an explanation.

[@jonahg6564]

Would you make a learn react tutorial? I feel like you’re an amazing teacher and it’d help a lot

[@CodingWithChaim]

I have been toying with the idea for some time now

[@jonahg6564]

Coding With Chaim ahhh I would love it if you have the time! I would watch full ads and view multiple times 😂😂😂🙏🏼🙏🏼🙏🏼

[@CodingWithChaim]

Lol 😂 yea there is a good chance I’ll do it

[@jonahg6564]

Coding With Chaim by the way thank you for the content you are already making!

[@CodingWithChaim]

Jonah G you are most welcome

[@saitejagatadi9711]

Great Explanation

[@CodingWithChaim]

Thank you!

[@selftaughtdev8267]

Nice! Thanks

[@lord4791]

Great Video

[@vikasni95]

Wow sir tht was an amazing tutorial, U hve just rocked sir, Sir ihve one request plz keep making interview tutorial like this on react, Tqu sir lots of love and support from india 🇮🇳

[@giovanyreyes4470]

this was helpful

[@user-pp1or5fl2d]

Plz, record tutorial "How to work with react-google-maps" with customization / markers / tooltip for markers, or just clone map from airbnb)

[@CodingWithChaim]

Thank you for the suggestion, I will add to the list

[@abhatti26]

17:28 , if we use index as keys in the list( not recommended ) , and delete a certain element of the list , does react delete it from the actual DOM rather than the virtual DOM ?. Is that the reason why the whole list gets refreshed ? please elaborate

[@alexeyvasilkov436]

is this a good idea to use index for key in list item?

[@VictoriousVipin]

Hi Chaim, I have a question about context What if i have grandchild component in a separat file than how would i get the access to Context that you have declared globally at line no. 4?

[@CodingWithChaim]

You need to export it and then import where needed

[@alexcc316]

omG I had to set the video to 0.75 haha. Very cool btw, thank you

[@fullstackprojects5615]

In your "Controlled vs Uncontrolled" question : Would your input reflect the keypress changes in case of Uncontrolled component? This part is not shown in the video.

[@SlimAndCherryTravel]

I'm only half way through. Holy fucking shit, Amazing, thank you, sir.

[@CsabaKiss69]

You should have a counter how many times you say "actually" . Joking aside, great content.

[@rainyoutthere7899]

A-w-e-s-o-m-e video

[@smartlessons2305]

A lot of projects require skill to work with datepikers, but there is no good tutorials for this topic.. Is it possible to create react tutorial, kind of "How to use complex datepicker" for example from airbnb, and to create really complex, for example two/three open calendars eith tooltip on every day/date and info in that tooltip.

[@CodingWithChaim]

I’m gonna look into this. It seems like a fun idea for a video

[@iliketocode6986]

I got big interview tomorrow haha 7 months after that one I bombed

[@CsabaKiss69]

8:15 Line 23, no wonder that the component is out of control. :)

[@karthikp6473]

hi there chaim, which course do you recommend to learn react... i was planning to go with maximillian's course on udemy

[@CodingWithChaim]

That’s a solid choice he’s a good teacher

[@karthikp6473]

@@CodingWithChaim thanks chaim! already started , going well for now

[@niyomwungerifabrice4182]

Very efficient

[@manastripathi2407]

Amazing

[@ilkhomjonkhudoyberdiev5619]

Thanks a lot

[@prateekkumar5028]

Can we use context in any part of the code or it has to be in a particular tree?

[@CodingWithChaim]

Can be used anywhere

[@otockian]

React literally took me 6 weeks to become an "expert" at. It's insanely simple, especially coming from doing Angular for many years. React was a damn joke to pickup. Angular does pretty much everything in a far superior way, except for how React handles state. I do like the new State stuff in React way better. But the biggest thing that really hasn't taken off in React world which funny enough is called Reactive Extensions. Far superior for handling real time data, way more efficient to have data pushed to you vs. polling.

[@andrewl5201]

React is hella simple, the hard part is just learning all the third party libraries that you need to make it do anything useful