100% do more refactoring videos, these are rare and idk if it's specifically your unique idea to do this, but this is actually gold content

Not gonna lie, this is extremely valuable information for junior developers (and even more experienced ones), thank you for sharing your knowledge, and by the way, your explanations are very clear

Great stuff! I've definitely been sleeping on the usefulness of maps! Subscribed :)

Nicely done! As a senior developer I can assure that your work here is a gem.

Very good! Yes, I want to see more of this stuff.

This is great, would love to see more of these.

Great work brother . Expecting more like this 👍👍

Keep doing these awesome videos. I find them so helpful!

The refactoring is just on point. Good work.

This is was amazing, would love to see more content like this

What an amazing video for someone who is learning react. Thank you for this!

I love these kinds of videos! Great stuff!

This is excellent! getting back into React after a long break, and your videos are a godsent. Keep it up!

I wish I saw this YEARS ago, that was awesome and insightful

Nice! This was a good example of simplifying the code. I think it would be interesting to see how you might word a review on an example PR like this one.

This is wonderful, this kind of content is very helpful

I'm a junior dev, and I was wondering why you choose map as the state data structure instead of a set, because you're not keeping the state checked per id, you're only keeping the ones that are checked. And even if you kept all ids and just toggled between true or false, in this context it still makes more sense to me to use a set.

Such a well-made video. Kudos to Profy,, this channel deserves way more subscribers and views!

Great video, really helpful for someone getting started!

Wow this video was actually amazing, that's wild!

Awesome stuff, would definitely love to see more of this. Liked 'n subscribed!

Great video! I would love to see more of these

Awesome. Would like to see more videos like this

Subscribed! I want more of this. 🤩

excellent i see a lot of general concepts i can apply, especially when implementing that none selected box, thank you

This Is really helpful as a junior dev myself!

Awaiting more video like this, Thanks for posting!!

Loved this kind of video!

Great video!

Absolutely loved this article. I read it last night and could apply it in some work I went back to today, where I'd added unnecessary state that I could've derived

thanks for this, helps a lot as a junior

Thanks. As a just learned react developer, this will help me

Thank you for this video! Helpful 💓💓

this was amazing and strangely therapeutic

Really cool video! Thanks!

WE NEED MORE OF THIS CONTENT

Very informative!

aah I could watch these all day. Loving it! Very tempted to send my code... hoy could I do that? Cheers!

I subbed, hoping to see more refactoring videos!!

Excellent refactor, well done

I'm not a junior dev anymore, but thank you for this insightful video. Personally, when I am preoccupied with the development or maintenance of a project, I sometimes form some bad habits, like lack of proper error handling in some logical cases, because the project needs to be developed quickly and I slack off while chasing the fast paced development of features. These types of videos really bring me back into reality and make me realize some of my newly acquired deficiencies in React.

A thought on the data structure you chose. A map works well. Whenever I see a map where the value is a Boolean, I ask myself if a Set would work instead. In this case, I think what you really want is a Set.

Great video :)

Great video Johannes! I had your blog on this lined up for reading for a year now. I saw the video and just went for it now. 😆

I would love to see more

more videos like this please!

thank you very much for the video

good video! I would make a habit of saying "simply" less often. what's simple and obvious to you might not be to others!

Hi, hope you will have more of this video series, or refactoring playlist. Thanks for the content! thumbs up!!

Thank you so much. If possible, please upload a video on how to develop a production ready react app, for example the folder structure, custom hooks, global context store, global axios confg, etc.

Do more junior refactor videos!!❤

very nice, clear and helpful for me as im practicing with react! although i needed to watch it in 0.75 but thats because im not native english 😅

Thanks for sharing. Cool work. One thing I could suggest is to split component into several smaller once.

For the first issue: Pasing an object as a parameter to fill can cause another major issue that all the object have the same reference. Here is an example: let arr = Array(5).fill({a:1,b:2}); arr[1].a = 6; //This will cause all a to be 6 for "all" the objects in the array

Damn, imagine watching these videos, joining a company as junior dev and writing such code what he wrote after refactoring.

Juniors code is better than some of the seniors where I work.

Amazing video ! May I ask when is it appropriate to use a map vs an array?

Do it just do it this is awesome

Boss level♥

Nice! Would be interesting to see how the solution can be extended for a filterable list

Last issue is not using typescript

please do more refectoring session

Unnecessary state variables are the worst.

I gotta say.. your tone and presentation is super monotonous, but the value of what you say and explain is great. Well done I agree with all you said. One thing about the Map though. Personally I dislike using Maps on very big data arrays, and simply revert to arrays + writing helper functions for search and filtering but a Map is much more readable and "easier" to use

wow, great work! how long would it take you to do these refators in real time? I imagine its not done typically within 20 minutes... thanks for the video

wow, more of this

Hello, as your map of completed issues only ever has a value of true, was the only reason you used a map instead of an array/set here so the lookup could be faster when checking if the issue is completed or not? A set of IDs seems to make more sense imo Thanks

I encountered this very same problem (diff example but same premise) and I tried to use a Set with redux toolkit, didn't want to work for some reasonso I had to resort to a dictionary/json where the keys mapped to any value (1, true, null, didn't matter). Then I replaced redux with zustand and it let me... how odd.

Interesting

This was very insightful. As a junior dev I learned a lot. Most importantly is that I really have to start using the new Map instead of just objects and I actually didn't know about the ".size" property. does it work with "regular" objects? Last question is a bit longer but since you touched on that subject I'll allow myself to ask that: I have an app in which I have a sidebar with buttons which run functions (ofc) and one of those uses the text in the main layout. In that case, using a ref felt like bad practice since I would have to either forward it through many cmps, store it in the global store or use context instead of just accessing it directly... what is your take on that? Thanks! :)

array is way faster then a map in this example. only in huge list it would make a difference that's not common to load all on the client side. a small array like this is even faster if you have to loop through it a few times then the overhead of having function for the map. but dont worry a lot of junior devs make that mistake

One question , the thing where you replace the for loop for counting elements that have the status open with a filtered array ( arr.filter().length ) just to have it just "pretty" impact the memory usage ? U don't just iterate thought the the array that you have , u create a new array so , allocating more memory .Maybe a middle ground can be a reducer :D

Omg u do it all so fast compared to me, it makes me cry🥺😭 But i wont give up 💪

Very good. I just don’t agree with ternaries being simpler that if statements. I know frontend developers tend to run from ifs as the devil does from the cross but I think ternaries are a common source of confusion and bugs in lots of front end code. Good job

Very helpful review. Thanks for sharing Although I'm still not able to understand one thing In the first line of handleOnChange method you doing this const updatedCheckedById = new Set(checkedById); (I have taken this from your blogpost , in the video it is Map) How come this update the previous Set and if so the next if check should return true, but surprisingly it is returning false Can you share some thought here Apologise for my lack of knowledge in advanced

a note on Map and Set Javascript structures. with Node.js it's fine to use them, but avoid using them on v8 (browser). V8 uses a ton of optimization techniques, specifically for basic array and objects that cannot be done for Map and Set's. to be even more specific, Map and Set cannot be cached as effectively and thus become slower than if it was otherwise implemented with a basic object or array. I'm not 100% sure if this is still the case but it was when this video came out.

im confused about the usage of !!, i understand it does a double negation and converts to boolen, but why concert to boolean if the value is falsy anyway?

Can i use Map, Set, Proxy, inside a useState Hook?

has-method fits here better 5:45

Can you point me to resources explaining the !! on the input's disabled attribute?

Hello MrBeast!

Instead of using a Map maybe just have an array of stateId's and use indexOf or includes instead of get on the Map its both faster and simpler because the truthiness is defined if it exist and dosn't carry a true value as well so its both faster and uses less memory

Can you add a live clock extension to vsCode so we can judge how long the rafactor actually took otherwise imposter syndrome starts acting up with all the time skips :D

As a senior swe, one thing I would nitpick is this awful double negation (!!). I would propose changing it to the Boolean constructor and adding a custom eslint rule disallowing UnaryExpression (!) as an argument of UnaryExpression (!)

I understand the convention that methods returning booleans should begin with `is`, since the assumption is that the method's object is the noun part of the clause. However, free variables are also nouns, not actions. I cannot help but feel that this convention being carried over to variables is a consequence of dogma, rather than usefulness. "IsIssueOpen" is a question, not a statement. "If is issue open" is not good English. Does anyone have an argument to counter this?

10:07 idk much about react, but readability was easier. Now Id make a comment above about the false states.

How did he delete the whole line at once??

Could have used a set

2:45 - I disagree about using refs to access the dom in 2024. Ref access was Reacts way of hiding their performance issues back in the day. But dom access is fine now. 10 years later good grief.

Very cool content but a bit too fast IMHO. 👍

bitflag, where?

I feel bad I just don’t understand

why doesn't this guy blink

Those are some long variable and function names lol

Wow Sar, how to become pero laik u

Mmmore of. This please

WTF is with the bot comments?

Love it, thanks from sharing.