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10 ReactJS Coding Challenge (💥Coding Interview Prep💥)

Let's Code on January 05, 2022

Last month, I posted 2 ReactJS interview questions 🎤 - Advance Questions and Commonly Asked Question and got a significant welcome by dev.to commun...

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armenic • Apr 12 '22

Thanks for nice challenges. I really enjoyed solving them! By the way beta.reactjs.org/ also started to include challenges. Maybe you can contribute to the new docs? They are open for public PRs.

Let's Code • Apr 12 '22

your welcome! ill definitely check that out. thanks for the link.👏🏻👍

Lovish Tater • Oct 5 '22

Hi armenic,
I want to contribute new challenges in beta.reactjs.org/. I don't know how to contribute, I saw React's git repo but I didn't understand how to start. can you please guide me.

Let's Code • Oct 6 '22

check this out - reactjs.org/docs/how-to-contribute...

Mary-Katherine McKenzie • May 26 '22

Great exercises! Had fun with these!!

One thing I want to note - in your solutions, I often see the pattern:

const [value, setValue] = React.useState(0)

<button onClick={setValue(value +1)}>Increment</button>

However, the React docs prefer this method of using the previous state value - passing a function that receives the previous state value.

const [value, setValue] = React.useState(0)

<button onClick={setValue(prevValue => prevValue + 1)>
    Increment
</button>

Updating state with value instead of using the previous state function may result in some buggy behavior because of React's unpredictable & async state-updating logic. Likely won't see anything buggy with these examples since they aren't too complex, but just wanted to shout out that nuance!

Thanks again for these great exercises!!

Let's Code • May 27 '22

yes, passing a function is way better and the right approach to handle setting state here. Glad that you found this post useful and you are very welcome. Will create more post/video like again.

Dan • May 7

It was fun! Thanks a lot!

Let's Code • May 13

glad that you've liked the coding exercises! thanks for the comment.

Manish Salunke • Sep 4 '23

I found this on udemy.
React JS Coding Interview Challenges and Exercises
udemy.com/course/react-js-coding-i...

its good.

Ionut Oltean • Feb 9 '23

Nice I always look for those kind of challenges to practice

Let's Code • Feb 9 '23

i plan on making more in the future. Stay tuned :)

Hemavathi • Feb 22

Very helpful exercises for beginners. Thank you :)

Aliafify • Apr 27 '22

thanks for that nice chalanges

Let's Code • Apr 27 '22

your welcome buddy! i feel great that this content helps many devs. 👍

Saty4Dev • Mar 15 '22

It's difficult for beginners (like me) to directly dive into building projects after learning React from online tutorials. Thanks for these practice problems, need more of these on React. :)

Let's Code • Mar 15 '22

ive been there before and i know how you feel. i’ll try to find more time and do more. i’ll post when i have something ready. thanks for the comment

abbydorso • May 25 '22

this is so helpful for interview prep, thank you!!

Let's Code • May 26 '22

helping engineers like you and me are the goal of this post and video.

I appreciate the comment and stay tuned for more post like this.

Isabelle Francis • Jun 25 '22

For create counter app challenge, i created two functions (decrease and increase) to be passed instead, later simply calling ....is that inline with best practise?

Let's Code • Jun 28 '22

it is and is common in any ReactJS applications

sandym • Oct 4 '22

I enjoyed this! Thank you so much!!! If anyone have anything similar please share! I would love to tackle on some more!
Thank you in advance!

Let's Code • Oct 6 '22

you are welcome!

Veronica Valenzuela • Mar 18 '22

This was so helpful, thank you!

Let's Code • Mar 18 '22 • Edited

your welcome Veronica! check the youtube video i have above for additional reference. Many found it useful as well.

Pcoch • Feb 4 '23

Out of curiosity, if you could do all of these quite easily without any external help/docs, is that a good sign you might be ready for a React Junior Dev role? 🤔 Or would we need to be answering the advanced ones?

Let's Code • Feb 8 '23

this is question is more tailored for experienced/advanced React Dev.

you can expect basic Q&A for React Junior Dev and small react exercises

Janice • May 23 '23

I found these exercises are too easy. Could you please mention that these are for absolute beginners somewhere in the header of the post? I doubt that any interview question would be this straight forward. Nevertheless, appreciate your effort on making the post, it has to be useful for someone 👏🏻