Learn useCallback In 8 Minutes

🚨 IMPORTANT:
Full React Course: courses.webdevsimplified.com/...
In this video I cover everything you need to know about the useCallback hook. I go over all the main use cases for useCallback as well as many common mistakes that developers make. This is part of a series of React videos where I cover all the important hooks in React.
📚 Materials/References:
useCallback Blog Article: blog.webdevsimplified.com/202...
React Hooks Playlist: • React Hooks
🧠 Concepts Covered:
- How to use hooks in React
- How to manage referential equality of functions in React
- How to use the useCallback hook
🌎 Find Me Here:
My Blog: blog.webdevsimplified.com
My Courses: courses.webdevsimplified.com
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Twitter: / devsimplified
Discord: / discord
GitHub: github.com/WebDevSimplified
CodePen: codepen.io/WebDevSimplified
#ReactJs #WDS #useCallback

[@nanonkay5669]

useMemo: Returns and stores the calculated value of a function in a variable useCallBack: Returns and stores the actual function itself in a variable

[@GuitarreroDaniel]

Thanks man!

[@h2o313]

good summary. I often found "useCallBack" is handy when you're passing the parent's setState function down to its children.

[@Vishal-ki2df]

Why can't we use useEffect instead of useCallback?

[@vijaykumarreddyalavala3713]

@@Vishal-ki2df Using useEffect you can run a function when a variable changes. But that does not mean that function will not run when the other state variables in your component change. Using useCallback you can make sure that the function runs exactly when you want it to run based on changes in a variable instead of everytime the whole component renders.

[@ParadoxWorks]

@@vijaykumarreddyalavala3713 Freaking nicely explained

[@pawandeore6989]

for someone who is confused the main difference between useMemo and useCallback is usMemo cache values and useCallback caches the function itself

[@pawandeore6989]

@@xlgnepoTechnically, you can achieve a similar effect by using useMemo to memoize a function, but it's not semantically the same as using useCallback. useCallback is specifically designed to memoize functions to ensure stable identities across renders, which is crucial for performance optimizations, especially when passing functions as props to child components. It's more explicit and conveys the intention more clearly. So while useMemo can be used for this purpose, useCallback is the recommended approach for memoizing functions in React components.

[@tomaszkapalka]

I am always impressed how you can explain quite complicated things in a simple way! As always...great job and many thanks!

[@davidserranoii4114]

Your understanding is inspirational. The biggest take away from this video im getting is to look behind the scenes to improve your code so you can run as efficiently as possible. Always look forward to your videos

[@oracleking4252]

I love this guy. He breaks it down!!!! Wherever I am, whatever mess I am in, I look for him to solve me problems. He's my personal full stack overflow

[@Shoulon]

This is really awesome. I was building a grid that was initially built from a function then would set it to state. But my other components would force it to rebuild everytime. UseCallback fixed this issue!

[@hamzafaysal909]

Just watched your useMemo video and I was really confused between these 2 hooks but this video clears everything... Thanks Kyle : )

[@stevereid636]

This is awesome. I’ve been wondering about the differences for ages. I feel like Kyle just granted me a super power 😎

[@markwillis1045]

Ha, I’m so glad I found this channel. I’m going to be busy watching these the next few days! 😀

[@sottitron]

Enjoying your hooks videos. Your video has a function passed into a component. It makes me think I'd really like to see a course or series on solving some of the trickier design problems with React. Specifically, concepts I've caught myself getting tripped up in my thinking with are: How to decide to use props, state or a store/reducer (and when to use context.) Strategies for interacting with APIs. When passing a function to a component makes sense. Testing your components when you're using hooks.

[@mohmarroun3189]

Thanks , I am always impressed how you can explain quite complicated things in a simple way 👍👍

[@simeonieroteev4555]

That explanation is very, very clear and useful! Thank you!

[@zdargahi]

you explain difficult concepts so clear and simple. Web Dev simplified, indeed

[@borisnekezov6620]

Thanks for that video, Kyle! The best and simplest way to understand useCallback!

[@angell2341]

Explaining the usecase on why we have to use that is really ausum, I felt ur channel unique

[@tadeuszjiwu255]

This is a very clear explanation, thank you very much, keep up the good work

[@aryanshmahato]

Desktop in introduction was looking dope! Great video BTW..

[@GrigorMinasyan]

So helpful! I had an issue where socket connection would get duplicated when toggling dark more

[@marcelotorreblanca9276]

I've been having a really bad time looking at the React documention about those hooks. And just when I was wondering about the difference between useMemo and useCallback: Boom!! you read my mind!! Just outstanding explanation!!!

[@andrewshaban2888]

You are a good tutor. This is a rare talent. Thank you very much!

[@KaaiSpeaksHisMind]

Beautifully explained, thank you.

[@johnhaupenthal]

Clear and concise, great video.

[@davidgentilli7944]

Thank you, Kyle. This explanation is incredibly clear and easy to understand.

[@frontendHacks]

watch useCallback Hook in Hindi in easy way explained kzbin.info/www/bejne/fZuZaaWEZdt_icU&ab_channel=Front-EndHacks

[@mrnabby4178]

The topic is crystal clear. Thank you man.

[@developerbuddyavikunj5996]

It was really helpful 🤗🙏 . Thanks alot for sharing. Finally got clarity on the concept.

[@logio7663]

Very clear explanation. Thanks a lot ! !

[@markwillis2336]

OooF! This is just pure gold. You just helped me out of a hole again Kyle, thank you so much!

[@simmzzzz]

Best tuts on the web - PERIOD. Thanks Kyle!

[@shivanyachandra4214]

Great video!! can you make a separate based on the difference between useMemo and useCallback, this will really be helpful!

[@jaytran247]

Super genius explanation. Thanks so much.

[@bek3634]

really simple explanation! thanks to you a lot.

[@thebetoxpro]

Amazing explanation. Thank you from Mexico

[@derekmoore7401]

very helpful and succinct. Thanks for your videos!

[@VishalSharma-rn7mt]

awesome tutorial, when I will have money, I will definitely buy your course brother

[@NITESHSINGHNRS]

bro....your explanation is to diff from others and have more details. keep it up.. superb

[@maor44]

Amazing work man! thank you!

[@iurii7752]

Great explanation :) Thank you

[@davidhahn7391]

great explanation! thank you.

[@johannesperez9548]

Crystal Clear, thank you so much!

[@keiferramos8858]

very true. You really simplified it.Good Job😌.

[@luaneaquino7835]

Thank you! great tutorial

[@Karlponken]

Great explanation! Thanks a lot!

[@ifillup]

Great explanation (again)!

[@rileykarl4895]

You and net ninja is a killer combo - thank for the great vids !

[@HOLONIA4EVER]

Amazing explanation !

[@mayankvora8116]

Awesome Explanation

[@hoyinli7462]

super clear. highly recommend this channel :)

[@vivarantx]

great man, you deserve great success

[@eshwarravikanti7659]

Great explanation!!!!! More power to you:)

[@larcho]

Awesome video. There quite a few videos here in youtube that explains this poorly, thanks for this.

[@rohith8269]

Great explanation!

[@lightrao]

Thank you, very useful !

[@shizasiddiqui1689]

You're brilliant Kyle.

[@Wakkyguy]

It would be very helpful if you could make a useMemo() vs useCallback() video demonstrating their practical usage in one sample project.

[@WebDevSimplified]

I have a blog post linked in the description which does a good job of comparing them to each other.

[@Wakkyguy]

@@WebDevSimplified Yes I have read that. Just wanted to see them being used in a single project.

[@guidoglielmi7992]

lt bugs me that useMemo(()=> ()=> [number, number + 1, number + 2]) would be the same as using useCallback

[@GreatAdib]

it can be used in search feature just use debounce an pass it to useCallback.

[@jnmldo]

Thank you so much for this video

[@jefersoncosta2621]

awesome!! U rock, thank you so much for this video.

[@ibrahimyoussef4489]

Wow!!! awesome I swear this lesson the real best lesson off all I get in this point and this always you

[@shane2023amazon]

concise and helpful

[@lakshyaagarwal4044]

what a wonderful example !!!

[@manishkumartripathi2259]

Nice explanation 😊

[@nihadyaqublu2359]

thank you for the video!

[@Stef-an]

These short videos are life-savers for juniors. Thanks a lot!

[@COROLOSTO]

And mids :p, oh wait, that means that I'm not mid lvl? oh man! :(

[@saarza9991]

​@@COROLOSTO we all are noobie poobies :)

[@naserpapi8921]

Excellent Thanks

[@neisservilla7239]

thanks you really help me

[@eldowado]

Hey man - love these videos, you seem to have one on every concept. I **think** I can throw you some suggestions to make your audio even crisper, without changing your hardware at all. If you're interested, we can give it a go - then I can maybe ask you some React questions in return, haha. Be well, mate!😁

[@kwaku_2023]

You are a blessing!

[@sergiyrudenko905]

you da best, bro!!! thanks!!!

[@xylvnking]

this one gave me a lot of trouble for some reason despite the other hooks not being too tough. the way i wrapped my brain around it is to remember that useCallback allows us to pass a reference to a function, whereas passing a regular function as a prop causes react to create a new function within the component on each render. useMemo allows us to avoid expensive variable calculations, and useCallback allows us to avoid redundant functions being created in memory. if I'm wrong PLEASE let me know lol

[@nishaindesilva3738]

thanks! this solve a major confusion in react. I always wondered why inner functional component resets on parental state update. the answer is useCallback() !

[@thecutedreamkostasp.4449]

Excellent show case of usecallback! But i wanted to mention that u could avoid usecallback there if u just out the function outside the App Component and just pass the number as argument on it! Then every time App component rerenders the function wouldn't generated again! Big loves for your channel!

[@mohammadsaadati2863]

Tnx very useful

[@AnoJlJloH]

You're the BEST!!!

[@yag7769]

Amazing, thankss

[@prince5922]

6:19 You can pass parameters using useMemo, from react documentation, the following. useCallback(fn, deps) is equivalent to useMemo((yourParameters) => fn, deps).

[@bibahbibah5108]

really u have simpleified to me

[@cyberwolf9543]

I got this BRO )) THANKS TO YOU!!! AFTER 2 YEARS NOTHING CHANGED ABOUT USECALLBACK BRO?

[@ritavdas7570]

Amazing video

[@blakelarson5005]

Great video

[@sudhansupradhan6891]

Awesome 👌

[@Bruno-ds8ze]

finally thankyou very much

[@lemon_maho]

Mannnn I was actually going to search for a solution to my problem, and then without me even searching, I see this video and I'm like : sure let's check it, just for it be the solution I'm looking for, now I'm off to use that in my code, thank you ^^

[@vinzbrain]

Great video! 2 questions: 1) wouldn't it not make more sense to pass the generated array to List rather than the function that generates them? 2) can useCallback be achieved with useMemo that that wraps a function that returns a function?

[@rajk1623]

I like the second question, I wonder the same.

[@rahuldwivedi4758]

Great work. But here’s the issue. The useEffect wouldn’t be called again in your List component as you have mentioned. But whatever inside your return is, will be re-rendered again. Put a console log inside the return block of list component to see. To prevent that you need to wrap the List component with memo, memo(List)

[@goharamin820]

thank you soo much

[@tinmank]

Hello, are you planning to make a simple login sample for React? What are the best practices? How about firebase? Most samples are using old class methods, but I really would like to make one with Hooks. should I get data with useMemo? or another thing I can't decide; how to use a different menu for logged in and logged out users. Thank you for your clean instructions. Best.

[@AndrewDevUA]

awesome!

[@abhilashreddy8724]

Thanks for the great video! If a parent component's state is updated will it rerender the child component or not? So, in this case, if the number is changed will it rerender the List component irrespective of useCallback?

[@yahya89able]

fantastic

[@alisherdotdev]

thanks Kyle :))

[@kose241]

you helped me get a job at coinbase, ty

[@lukisIVIII]

You're the best teacher! You have a true gift, thank you!

[@DediAnanto]

Thanks, for beginner like me, I rarely use useCallback if my editor don't suggest it 😄

[@exoticcoder5365]

Great !

[@njayman]

Thanks

[@Johnny-rn8fb]

Thanks

[@snarkykat]

Congratulations on your engagement :)

[@Cloud-577]

how do you know?

[@snarkykat]

@@Cloud-577 It was on Twitter

[@StephanHaewss]

From the docs "useCallback(fn, deps) is equivalent to useMemo(() => fn, deps)", so it is just a shorter way for memorizing functions as I understand it. Anyway, good video!

[@naveedalirehmani4135]

So the main difference between useMemo and useCallBack is that one returns the value of the function and the other returns the actual function, but what if I use useMemo and return a function as the return value. will it work the same or am I missing something here? Like this. const functionWithMemo = useMemo(()=>function(){})

[@StephanHaewss]

@@naveedalirehmani4135 As I understand it, this is equivalent to useCallback, yes.

[@satindersingh9671]

You are the best

[@ridl27]

ty.

[@goharamin820]

amazing