Why I Don’t Use Arrow Functions With const/let

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  • čas přidán 6. 08. 2024
  • Arrow functions are great. I love how concise and easy to read they are, but I only use them in a two specific situations. In all other scenarios I use normal functions. In this video I talk about what those two scenarios are and why I prefer to use normal functions in all other cases.
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    ⏱️ Timestamps:
    00:00 - Introduction
    00:38 - #1 Reason I Use Normal Functions
    02:35 - When I Use Arrow Functions
    05:09 - Another Reason To Use Normal Functions
    #ArrowFunctions #WDS #JavaScript

Komentáře • 531

  • @fabianramirez3222
    @fabianramirez3222 Před rokem +258

    The first reason is actually why I like arrow function over classic function definition. Code flow for me goes from definition to implementation from top to bottom, instead of what you mention about "important" code at the top. If I need something I like to know this "something" exists before trying to use it, and using arrow function along const enforces just that.

    • @alesholman801
      @alesholman801 Před rokem +7

      I was thinking the same thing !

    • @eavdmeer
      @eavdmeer Před rokem +11

      Same thought here. I would never have the important stuff on the top. Especially because of how hoisting works. If you can't always do it, you should never do it

    • @eavdmeer
      @eavdmeer Před rokem

      @@Shulkerkiste it absolutely makes sense just for brevity to put functions in constants,especially so with arrow functions. Of course not when you write them out with all the superfluous brackets he was using and a useless 'return' statement.
      And however clean your code is, the constants you need must be declared before you use them, whether they contain functions or other values

    • @dany_beltran
      @dany_beltran Před rokem +4

      If it's about code flow, it's not like classic functions can't be moved to the top.

    • @MaxPicAxe
      @MaxPicAxe Před rokem +7

      Similarly, we don't put import statements at the bottom of the code

  • @ProwlerDigital
    @ProwlerDigital Před rokem +6

    It’s refreshing not seeing a title like “STOP DOING THIS” whenever I see that, I just scroll passed the video

  • @Radek11boss11boss
    @Radek11boss11boss Před rokem +498

    The first reason is why I use arrow functions, i have to have some structure in my code not random mess with fn declarations between usage

    • @indriq78
      @indriq78 Před rokem +27

      utilizing hoisting and putting the actual solution on top is less messy than putting a ton of "intro" in front of the important part.

    • @wisdomeispower
      @wisdomeispower Před rokem +15

      True, you need to create function thene use it, this is how code should work. If hoisting were good thing let and const would have hoisting to. You should always create function thene use it no metter if you are using function expression or decloration.

    • @rand0mtv660
      @rand0mtv660 Před rokem +12

      @@indriq78 That is really highly subjective. I personally dislike if a function on line 10 is calling a function that's on line 100, I don't really care if the most important logic is first in the file or not, I just care that things are defined in order so that they are defined before they are used. It's just easier for me to piece together things if they aren't just randomly spread throughout a file. I can also read two things at the same time on same IDE/editor page if I have two functions one after another, but the second one is calling the first one. I can just have both of them in the same view without using multiple editor views or whatever.
      I feel the same way about variables as well, but with variables it makes more sense to have them defined before using because variable hoisting is just weird in normal code flow when reading code.

    • @gabrielemarino1360
      @gabrielemarino1360 Před rokem +16

      I just move all the functions to another fileto have a cleaner environment

    • @thekwoka4707
      @thekwoka4707 Před rokem +5

      @@indriq78 but the functions in this case should be in another file...

  • @ribasenric
    @ribasenric Před rokem +367

    This IS the reason I like them. :)
    Put helpers functions in another file and load it

    • @Raxxman
      @Raxxman Před rokem +6

      ditto

    • @raellawrence7116
      @raellawrence7116 Před rokem +18

      Yeah. If all the helper functions are hidden at the bottom of the logic, that seems like code that is not easily shared and is at risk of repetition.

    • @CWhitmer22015
      @CWhitmer22015 Před rokem +1

      I was thinking the exact same thing.

    • @TheShizz41
      @TheShizz41 Před rokem +3

      100%. Makes the code that runs with helper functions easier to debug when you can just put it side by side with the helper function file

    • @LogicEu
      @LogicEu Před rokem +11

      Also makes much more sense coming from any other language where you need to declare your functions and classes before you can use them.

  • @MaxPicAxe
    @MaxPicAxe Před rokem +96

    My opinion.
    1. Hoisting -- I personally prefer to write code in this order anyway, the outer layers (i.e. the main logic) is further down, so I always jump straight to the bottom of a file if I want to know what's getting executed. I guess this just might be preference. I also come from a background of pure mathematics where everything is structured in a way where there is no hoisting, everything is ordered naturally, that is, sequentially.
    Regarding your example with helper functions, these can always be moved to a different file, that makes more sense if you believe there should be a separation.

    • @NickCombs
      @NickCombs Před rokem +3

      Although the IDE helps with this to some degree, it is generally more difficult to find the function from an invocation if they are split between multiple files. Still, I appreciate the different viewpoint. Looking for the top-level calls near the end is probably more natural for coders who are used to more imperative programming styles.

    • @theblackunderflow1842
      @theblackunderflow1842 Před rokem +4

      Coming from a C++ background, I anticipated that function declaration before its usage was the norm..

    • @tuananhdo1870
      @tuananhdo1870 Před 3 měsíci

      good point here. I think they have a reason to add the strictness to "const"

  • @dasten123
    @dasten123 Před rokem +24

    I agree on using the function keyword for defining small helper functions. But I still like to define them before using them.

  • @devhelp
    @devhelp Před rokem +73

    Slight correction in your event handler, "this" is the same as event.currentTarget, not event.target. The target is the element that was clicked on while currentTarget is the element with the event handler.

    • @phillipandrew87
      @phillipandrew87 Před rokem +2

      In some cases, such as this one, it would be the same, though it's definitely an important distinction to keep in mind.

    • @redsnflr
      @redsnflr Před rokem +1

      yeah, just to make it a little clearer:
      (i) event.target is the node where the handler function was written
      (ii) event.currentTarget is the node(parent) where said handler function bubbled up to - where event currently is being handled.

    • @phillipandrew87
      @phillipandrew87 Před rokem +2

      @@redsnflr Not sure what you mean by where it was written. The handler is called (I think you may have meant this?) when the element, or descendant of the element, that the event listener is registered to is clicked (if it's a click listener, as is the case here). If there are no descendant nodes, or if you just click somewhere in the parent where the child is not, e.target will then equal e.currentTarget, ).
      If anyone wants to better visualize it, just search event propagation for some easy to understand diagrams.

    • @redsnflr
      @redsnflr Před rokem +1

      @@phillipandrew87 yes, where it's "handled" is where you write the event handler function, e.target is static but currentTarget is dynamic based on where the event currently is.

    • @phillipandrew87
      @phillipandrew87 Před rokem

      @@redsnflr Okay, I see what you were saying. By the way, just so no one who reads this gets confused, e.target is dynamic, e.currentTarget is static.

  • @brett84c
    @brett84c Před rokem +1

    Love your channel, man. I love that your videos are concise and straight to the point. Learn a few new things everytime I watch your content, even if it's a topic I already know well and you give me a different perspective on it.

  • @catsgotmytongue
    @catsgotmytongue Před rokem +17

    as an engineer who has coded in many languages over 20 years, JS is the one that is the most painful to deal with BECAUSE of 'hoisting' and the changing context of 'this' depending on how it's called. Among other things, JS has so many odd quirks that make it a pain compared to many other languages.

    • @Albert_Hall
      @Albert_Hall Před 11 měsíci

      it is A POWER of JS, it is it's POWER !) not a weakness or a pain, it is it's POWER !)).

    • @jcasimiro2788
      @jcasimiro2788 Před 10 měsíci +1

      hey man, if i wanna became a backend developer what language would you recommend to start?

    • @oohkumar
      @oohkumar Před 9 měsíci +2

      I feel your pain. The descriptions of the this keyword across tutorials on CZcams are confusing. I would start by looking at tutorials on the execution context. Once you get that then topics such as hoisting, scope and the this keyword become clearer. czcams.com/video/Nt-qa_LlUH0/video.htmlsi=bvcDZ-ET88oZeT_R

    • @IvanKleshnin
      @IvanKleshnin Před měsícem

      "Dynamic this" solves an Expression problem though. It would be a disaster to simply remove it. An alternative object extension mechanics would have to be provided before that.

  • @darklorddracula512
    @darklorddracula512 Před rokem +5

    Why would you define the utility function in the same file you call them ?

    • @trappedcat3615
      @trappedcat3615 Před rokem

      Not all functions are utilities beyond 1 file.

  • @OrelNaya
    @OrelNaya Před rokem +30

    for the first reason you mention, I think it's better to split the code to multiple files so when you use them you just import them where you use them

  • @yorutamashi
    @yorutamashi Před rokem +9

    i think that calling things AFTER defining them makes much more sense, I get super confused when the file doesn't have to respect a specific order... and seeing that so many people do terrible crap when they are not forced by linters or interfaces like typescript, I think it's very much needed to adapt to these better practices

  • @undisclosedperson3871
    @undisclosedperson3871 Před rokem +7

    Reason 1 is also why I use arrow functions. Not out of puritanical belief or anything, but the backend language I work with the most is F#, which requires everything to be declared before it can be used. And when writing functional Javascript (or especially Typescript), the languages are actually extremely similar and I think it's the best functional approach. F# enforces order of files too, which can't really be done in Javascript, but I wish it could be.

  • @codingman313
    @codingman313 Před rokem +2

    I think arrow functions do not require context switching, I may be wrong. Thus for small snippets of code I prefer using arrow functions and for larger snippets I use normal functions. As for organizing code, whether I write code at top of my file or bottom doesn't matter to me that much due to modularity, I do not write any thing else in the main script rather one main function and then calling it. But that's just my style. Honestly I do feel all the rules and guidelines for writing clean code is meaningless if your code is not performent. Most of the time this leads to unnecessary abstruction that often have many unnecessary instructions that are not needed but still called only to keep the structure "clean". For example, looping over same array multiple times in different functions where everything could be done in a single loop causing much less memory access (one of the biggest bottlenecks). Javascript is not a compiled language, but and interpreter. So from compiler diesign perspective, the optimization done by jit compilation is no where near like languages like c, where compilation in release mode throws away all the fancy abstruction and completely reorganize only performent code. Sadly dueto the dynamic nature of js and being and interpreted language this is not possible. So developers should be mindful of the cercumstences. However again it depends on how performent one wants his code to be. For a dataview kind of website it doesn't matter, but for things that requires high amount of computation it matters. As an example, working with canvas 2d if you floor the arguments before passing them to the function, you will see a significant boost in performance. The reason is simple, interpreters are not as smart as compilers when it comes to optimization.
    The point I want to make is that function calls have costs .

  • @ZakiWasik
    @ZakiWasik Před rokem +15

    On a real production project I almost certainly will have each of my functions in a separate file (excluding anonymous functions and callbacks) and when passing callbacks I usually want to bind the parent context like it is default with arrow functions, so I'm the opposite: I use the function keyword only when an arrow function does not cut it. Which is rare.

    • @NicholasHarris
      @NicholasHarris Před rokem +2

      Yeah, the example util functions given are great examples of functions you'd never even have in the same file as where they're being used in the first place. Sure, having the functions below the main logic of the file makes sense, but having those functions in a different file entirely makes even more sense. At which point using function keyword vs arrow functions don't really matter in terms of readability anymore.

    • @arjix8738
      @arjix8738 Před rokem

      One of those rare cases is when you want to use the arguments keyword!!
      Like, you made a callback, but there are no docs, so you print out all the arguments of the callback, this doesn't work with arrow functions sadly

    • @ZakiWasik
      @ZakiWasik Před rokem

      @@arjix8738 any cases where you could not just use the rest parameter?

    • @arjix8738
      @arjix8738 Před rokem

      @@ZakiWasik it's a matter of preference, I prefer arguments when the arguments are unknown

  • @rodrigolaporte274
    @rodrigolaporte274 Před rokem +21

    Ok, so now I have two things I disagree with you: not using semicolons, and now the arrow functions :P
    To me, having to define the functions before they're used is not an issue, but a plus. It helps when you work on a team where usually a few devs are messy with their code, so these small things that force you to be a bit more organized are really helpful. Same goes for some people's neverending creativity for using 'this'. With arrow functions we avoid several errors that cause bugs. So in the last few projects I've worked on, we use the opposite strategy: everything's an arrow function except for some specific cases.
    As for the syntax, it's just preference/getting used to.
    Anyways cool video, it's nice to see different approaches / trains of thought.

    • @Issvor
      @Issvor Před rokem +3

      WDS has some hot takes and I think he's doing it for the controversial comments and views. Almost every short I've seen from him is just objectively bad, but it drives a lot of views and comments. Most of his project tutorial videos have much better information, but the individual "why I don't use X" videos blow. His "why I don't use the useEffect hook" video is a golden example of a really awful take for no reason other than rage bait

    • @oyuu6565
      @oyuu6565 Před rokem +2

      I think for react is more cool and clean code to work with arrow functions with const/let, because you won't doing any hoisting since your state and stuff is being defined at the top of your component function, and any helper/handler function as well don't need to be hoisted

    • @IceMetalPunk
      @IceMetalPunk Před rokem +5

      @@Issvor Assume mistake over malice. I don't think he intentionally does it for rage bait; I think he's just mostly a self taught and solo developer who doesn't have all the information.

    • @Issvor
      @Issvor Před rokem

      @@IceMetalPunk That's a fair point

    • @MrMudbill
      @MrMudbill Před rokem

      I haven't seen this useEffect short but I personally put a lot of effort into avoiding using useEffect due to it's re-render strategy and awkward handling. However, I don't avoid it at all costs. Sometimes it's the perfect (or only) tool.

  • @MYount
    @MYount Před rokem

    This is really helpful. I am always trying to find ways to use arrow functions. You make a great point here. Thanks.

  • @neontuts5637
    @neontuts5637 Před rokem +7

    Thanks for sharing Kyle. I prefer to use the utils file to store the helper functions and import it to the main file.

    • @redsnflr
      @redsnflr Před rokem +3

      depends on the size of the app and how often you're going to reuse the helper functions.

  • @afzalhamdulay
    @afzalhamdulay Před 3 měsíci

    this video wasnt much much about syntax but more about logic. this was actually awesome knowledge that you gave. thanks!

  • @feynthefallen
    @feynthefallen Před rokem +7

    You make a lot of good points there, especially the ReferenceError which I honestly hadn't come across yet, because I work with nested functions almost exclusively. Maybe it also has something to do with the fact that to me as an old C coder defining a function before use is as natural as breathing.
    The reason why I love arrow functions so much is because unlike all the syntactic sugar around functions, classes and methods todays programmers grow up with, assigning an arrow function is very close to the bare bones of functions, which, when all's said and done, are very little but an address to jump to in memory.
    I must say, I disliked JavaScript for the longest time for its lackadaisical typing and conventions, but ever since I began looking at it from the bare-bones perspective, it has fast become my favourite language, even before Lisp and my beloved C

    • @rohithgoud30
      @rohithgoud30 Před rokem

      Yes even I didn’t face in react but maybe its issue in vanilla javascript I use it still I have a habit of writing function in order then call them at the end just like other programming languages 🥲.

    • @redsnflr
      @redsnflr Před rokem

      do you use Typescript given your JS typing issues?

    • @feynthefallen
      @feynthefallen Před rokem +1

      @@redsnflr Funny you should ask. It took me a while to discover TypeScript, but I instantly fell in love all over again 😉 Honestly, it's not "proper" hard typing, but that's what makes it so interesting - it holds a mirror up to your coding habits showing you what hard typing made you take for granted.

  • @mukhammadakilov2828
    @mukhammadakilov2828 Před rokem

    Thanks for excellent video and Happy New Year!

  • @user-pq1br4di8u
    @user-pq1br4di8u Před rokem

    Really Nice video. Thanks for the clear explanation!

  • @dweblinveltz5035
    @dweblinveltz5035 Před rokem +4

    I always default to arrows unless I need to create a new context. I'm not bothered by functions clogging up the top of file because they probably belong somewhere else if you have that many of them.

  • @CreatorX64
    @CreatorX64 Před rokem +4

    Good points, but this convention breaks as soon as you need to type a function in TypeScript (think of FC). Plus, I've found that relying on hoisting generally results in poorly organized codebases unless you're working on a tiny project w/ a single file (where arguably convention wouldn't matter that much anyway). If you think "what if I want to run some code in a utils.js file where I export my helper functions?", then I would say look back at your architecture and think whether you really want to run arbitrary code in a utilities file that's meant for "utilities". Idk, these are some of my reasonings to use arrows everywhere (except in OOP & decorators). Everyone should use the approach they feel most productive in as long as they know the differences between them 💙

  • @darklorddracula512
    @darklorddracula512 Před rokem +9

    The main reason I would use const arrow is the fact that they can't be modified. If you do (with a function) formatNumbers = [1, 3] somewhere bellow It would "destroy the pointer to the function itself".

    • @BritainRitten
      @BritainRitten Před rokem

      Basically you should prefer not to mutate almost anything unless it's better for a specific case for some reason (readability, performance, can't do otherwise, etc). So mutating a function should pretty much never happen - whether you define them with function or const

    • @IceMetalPunk
      @IceMetalPunk Před rokem +3

      @@BritainRitten Right, and being able to define a function as const enforces that.

    • @ja31ya
      @ja31ya Před rokem

      @@IceMetalPunk If you need to enforce the idea that you shouldn't be mutating a function reference, then you almost assuredly have far more serious problems within your team...

    • @soniablanche5672
      @soniablanche5672 Před rokem

      @@BritainRitten how do you mutate a function ? lol

    • @thecoolnewsguy
      @thecoolnewsguy Před rokem

      @@soniablanche5672 maybe by just declaring it again

  • @subliminakeys1674
    @subliminakeys1674 Před rokem +1

    I thought I was alone with this concept. I hate using const over function. Most of the reasons you said but primarily because when I'm scanning code for a variable or function I don't want everything to look like a variable. And hoisting, I don't want to worry about where I'm defining my function.
    The funny part is it's not even really any shorter of syntaxes. Const name () => is is literally one less character than function name() . You can omit the brackets in arrows but I often use them anyway.

  • @re.liable
    @re.liable Před rokem +1

    I know about hoisting but I don't rely on it. I write regular functions as much as possible on the "top-level" to take advantage of the `function` keyword as you mentioned, and at the top of the script so that it "flows" naturally

  • @abc_35p
    @abc_35p Před rokem +2

    I use function expressions at work because that's what's used there and it's not important enough to rock the boat. But I really dislike them in most cases. I find regular function declaration syntax much easier to read. I use arrow functions a lot, but as in the video, mostly when defined inline as a callback, or if I need to close over `this` (very rare). Hoisting is sometimes annoying but mostly not an issue since most of my functions will be in module files rather than defined where used.

  • @shawazonfire
    @shawazonfire Před rokem

    thank you so much, videos like this one (efficient, dense, clear) help me fill in the significant gaps i have in my knowledge

  • @RandomChanel6150
    @RandomChanel6150 Před rokem

    That's a good reason, I also like to have details of implementation at the end of the file below everything else. But there are ways around functions declaration (is that a right name for using function keyword?).
    When (if) you use react components you can just put helper functions at the bottom, as the component will be ran later than those, so they will exist at that point.
    Also those helper functions can just go to a separate file (which they probably should).
    So I usually still use const/let functions.

  • @The1stKing
    @The1stKing Před rokem

    I just watched the intro part and I'm already sold. 😊

  • @sawan34
    @sawan34 Před rokem

    Hi kyle, I do agree with your point. I just want to add one more point where we should not use arrow that is at the time of declaring prototype `Array.prototype.someFunction ` , please validate this point am i right or wrong ?

  • @BlurryBit
    @BlurryBit Před rokem

    Makes sense! I knew the fact but never really thought about it until now. :)

  • @ToadyEN
    @ToadyEN Před rokem

    I don't use arrow functions with const/let but didn't even think why. Thank you for telling me why 😂

  • @danzanity
    @danzanity Před rokem

    Great vid, I’m an sdet coming from c# and transitioning to Js, your vidz really helped me

  • @nicolajbro9545
    @nicolajbro9545 Před rokem +1

    I devide my code in sections, one being helpers functions, all declared with arrow functions.
    Later I have one update function, which all actions go through, so I’m never in doubt whether I’m looking at a helper function or the core of it, because there is only one core update function. The rest is helpers and sometimes i move to another file and have them all imported. Nice and clean 😊

    • @kodraa
      @kodraa Před rokem

      im intrigued, can you put a small example on codesandbox or something?

  • @quantumastrologer5599

    Super helpful, thx!

  • @syedaamir5745
    @syedaamir5745 Před rokem +1

    hey kyle
    hope you are doing great 😊
    could you please make a video to configure the react for production env. instead of CRA.

    • @Zagoorland
      @Zagoorland Před rokem

      He uses vite. Its super simple to set up, just follow up terminal prompts

  • @HarshKapadia
    @HarshKapadia Před rokem

    Woah! Thank you for this!

  • @photofrode
    @photofrode Před rokem

    How do you prefer writing "classes" and inheritance (or composition) in vanilla JS?

  • @srleom
    @srleom Před 2 měsíci

    I agree with Kyle here and use normal functions for helper functions and arrow functions for callback functions. It's much easier to identify a function this way, plus hoisting is a bonus.

  • @gmg8771
    @gmg8771 Před rokem +26

    Why do you want hoist arrow functions, they're introduced in javascript for the specific cause. I don't understand the argument here.

    • @ireallyamayuube
      @ireallyamayuube Před rokem +9

      Yeah. It's like saying "I don't use Typescript because it's more work". Correct (in a sense), but that work is there to actually make the code less likely to throw errors along the way, when the project grows much bigger. Hoisting is ok for small script and such, but I would avoid it as much as possible if growth is expected.
      Also maybe I'm weird, but I like the arrow look, especially with no parameters it looks like it's taken from an ancient occult book lol

    • @firedforfighting
      @firedforfighting Před rokem +7

      He never said he wanted to hoist arrow functions, he simply said why he uses one over the other. Those are two different statements

    • @gmg8771
      @gmg8771 Před rokem

      @@firedforfighting I wrote what i understood from the video, but I side with arrow functions coz I want errors to be thrown at development stage and not at the prod stage if they went unnoticed while using regular functions.

  • @Zeero3846
    @Zeero3846 Před rokem +1

    I always look at the very top or the very bottom for top level code, and quite frankly, I can never tell if I'm at the top or bottom at first glance anyways, because the IDE saves the scroll position. Plus, if you have the code overview scrolling panel, top level code will straight up look different, unless you're a monster.

  • @nashishere
    @nashishere Před rokem +1

    If you use typscript like almost everyone else, then that means your code will be transpiled into es5 anyways, hence your functions will be actual functions regardless of the declaration method and be hoisted anyways. i got your point tho

  • @hicoop
    @hicoop Před rokem

    Never thought of functions this way. Thank you!

  • @codebymoonlight
    @codebymoonlight Před rokem

    Wow. Awesome to finally see a Kyle video I don't agree with after many years

  • @monafdaod2133
    @monafdaod2133 Před rokem

    Thanks, kyle
    It was a great comparison

  • @MailarYT
    @MailarYT Před rokem +1

    If you have helper functions, I would maybe share the main code in smaller pieces, so you can put those functions into their own files and then use it on the main code.

  • @Rocky.G
    @Rocky.G Před rokem

    i m a full stack developer.. I know this concepts.. but refreshment of this concepts and
    the explanation in your videos gives my mind a kind of comfort and boosts confidence for unknown reason..
    keep up the good work friend.. your video was inspiring for me to keep working as dev !!

  • @christopherk4166
    @christopherk4166 Před rokem

    Another game changing video! Thanks!

  • @mrmibes
    @mrmibes Před rokem

    I had the "this" problem two days ago and could not understand why the arrow function didn't work, and the function did. Thanks for explaining it! I ended up just telling the linter to ignore my function, lol.

  • @dindustack
    @dindustack Před rokem

    Thanks for sharing

  • @bronstein007
    @bronstein007 Před rokem +13

    Definitely the most important reason for understanding whether to use ES5 or ES6 function syntax is with 'this' binding, especially when it relates to creating methods. That is actually important for the functionality. While I appreciate and understand your 'main reason' for better layout flexibility with hoisting, it is simply personal preference and isn't as important imo. Either way, thanks for the reminders. 'This' is and will always be confusing forever.

    • @leandro-siqueira
      @leandro-siqueira Před rokem

      You last frase defined me. Imagine learn "This" in a language that isn't you native one. It's so confusing 😂

    • @MrMudbill
      @MrMudbill Před rokem +3

      Haha, good thing we're mostly past using `this` in JS these days since there's a much bigger focus on functional programming. I don't think I've used `this` for years since when I did jQuery stuff. And I'm happier for it.

  • @michelaveline
    @michelaveline Před rokem

    Kyle, have a great 2023!

  • @randompointlessness2766

    on the other hand, what's the price of memory / extra processing to gain that hoisting functionality ?

  • @MarkParsonsCPA
    @MarkParsonsCPA Před rokem

    The syntax is much nicer when writing call backs but I write function else where because it's confusing to read? Just a heads up, you can use those named functions before you declare them because the engine has to read and handle a named function and puts it into memory. I get that memory is cheap... but it's not infinite. So you may be placing something into memory that you may never call.

  • @subscreibe_productions
    @subscreibe_productions Před rokem +2

    Happy New Year Kyle! ❤

  • @jacobphillips9235
    @jacobphillips9235 Před rokem

    Thank you! I 100% agree.

  • @ansariextc1
    @ansariextc1 Před rokem

    Thanks, really helpful.

  • @ThaRealIansanity
    @ThaRealIansanity Před 10 měsíci

    Interesting take. Like a lot of the commenters, I define/declare functions at the top whether using the function keyword or arrow functions. I'll even look at my code below and go back up and cut/paste the functions in the order in which they are called. It just works with my brain that way. But I think one advantage to putting your "important code" at the top is that once the functions are written and tested, you might argue that there is no need to see them because when writing the "important code" and using tested/proven functions, you don't need to be concerned with the implementation. However, that is one of my issues. I always concern myself with the implementation. Slows me down sometimes. 🙂 Another thing I will say is that sometimes it takes a second to see whether something is a function or a const variable if they are all bunched together so it becomes more important for readability to use white space properly and have some order to defining const someFunc => oneliner; vs const someVar = value;

  • @sergeibaskakov1014
    @sergeibaskakov1014 Před rokem

    Hi! Thanks for the video, but I may have misunderstood the first reason because English is not my native language, but it doesn't matter which type of function declaration you choose, arrow or old-style declaration, in any case, hoisting won't work with const or let. That's why the first example is not quite true in your statement. The second reason is the main difference between the two function declarations, because the function call depends on the context in which this function is called.

  • @atalhlla
    @atalhlla Před rokem +1

    I’m almost always dealing with other people’s code right now so my own preferences are pretty mercurial, entirely down to how I’m feeling on whatever small project I’m working on. I’m usually consistent within a project, but across projects it can vary.
    I think I usually use regular functions when just defining them in a module because when I’m naming them arrow functions don’t save much if any typing. That’s about it.

  • @MauroBonfietti
    @MauroBonfietti Před rokem

    You are great at explaining. Thanks for your videos! 🤩

  • @JeremyBolanos
    @JeremyBolanos Před rokem

    Great example! 🧑🏼‍💻

  • @mrmivpushkin
    @mrmivpushkin Před rokem

    I mostly use an arrow function as an equivalent to lambda in python. Other reasons are for dynamically changing class functions like for example the on_message of a websocket, as you described functions in objects or to define the function in a loop function like forEach etc. For the rest just the classic function as it is more readable and clear imo.

  • @codecleric4972
    @codecleric4972 Před rokem

    A lot of people commenting about putting helpers in another file... A couple things:
    1) Definitely do that. I think Kyle already knows that's best practice. But for the sake of brevity, he makes his point here not mentioning it.
    2) If you DIDN'T do that, and kept all helpers in the same file, I think what Kyle says makes perfect sense -- important logic at top, function definitions below.
    3) Either way, for DECLARING functions, I agree that the traditional function syntax is clearer -- yes even when declaring them in separate files/modules.
    4) Arrow functions are awesome, but 99% of the time I use them I would agree with Kyle here -- it's in the context of anonymous lambdas.

  • @RyuBateson218
    @RyuBateson218 Před rokem

    I love these cleaner code vids.

  • @arthurverot7089
    @arthurverot7089 Před rokem +1

    When you use typescript, it doesn't matter if you use arrow functions or functions, it wants you to declare them before calling them.

  • @maximroslow
    @maximroslow Před rokem +1

    As a react developer I always use arrow functions, but examples in this video is cool, it's good to know this stuff

    • @MrMudbill
      @MrMudbill Před rokem

      Personally I like definining react components as `function`. E.G. `function App() { return }` rather than `const App = () => { return }` (assuming you have some logic in it). However, the benfit of arrow functions in React can be for TypeScript typings, like `const App: React.FC = (props) => { return }`, but I find these explicit types unnecessary since the implicit ones are IMO just as good.
      But I've used both styles, and at the end of the day, the most important thing is consistency within a project, and harmony with other devs :D

  • @akillersquirrel5880
    @akillersquirrel5880 Před rokem

    My preference is to use arrow functions only where there's an immediate return, or if I need the outer this.
    `function a(b) { return b+1 }` is less typing than `const a = (b) => { return b+1 }`, but more typing than `const a = (b) => ( b+1 )`.
    In general, this allows the reader to quickly make assumptions about the code - if you see `=> {`, you know to look for a `this` referencing the outer block

  • @novanoskillz4151
    @novanoskillz4151 Před rokem

    At work we just use modules for commonly used helper functions and import them. For things like onClick functions we use arrow functions defined at the top of the react file underneath the useState declarations.

  • @marouaniAymen
    @marouaniAymen Před rokem +2

    Inside my React components I use arrow functions to implement event handlers and inner functions, I rarely found myself relying on the 'this' construct. But I think it's ok.

  • @MaxProgramming
    @MaxProgramming Před rokem +2

    Finally now I'm not alone with this opinion

  • @ky3ow
    @ky3ow Před rokem +26

    as solo dev its okay but when you work with code that someone else wrote, hoisting is pain in the ass
    because in comparison, if there are no strict rules where we should place functions, hoisted functions is immediate "peek definition", because they can be lower in file or higher, whilst arrow functions enforce you to define them before using, that makes them not significantly easier but quite a bit, also no "this"
    after dealing with class components in react i truly started hating hoisting

  • @mrwensveen
    @mrwensveen Před rokem +1

    I will use const arrow functions when I pass them around as callbacks or for some other reason. I like the idea that const (or let or var, ugh) defines a variable and passing something around requires a variable. Passing around a normal function works fine but feels icky for me.
    Also, and I'm not sure it wasn't intentionally to hide your "important code", your arrow functions at the top didn't need to use return statements. E.g.:
    const doubleNumbers = numbers => numbers.map(n => n * 2);
    I do define helper functions at the bottom, like I would define private methods in other programming languages.

    • @MrMudbill
      @MrMudbill Před rokem +1

      Agree, passing regular functions around just feels... weird. I guess it's just the concept of it that feels loose and risky.

  • @re.liable
    @re.liable Před rokem

    Inner functions are where I'm most conflicted at. If I'm writing closures, I'll write the inner fn in the regular syntax.
    However if it's a fn that is used as a callback in e.g. event listeners and I'm taking it out of the function call for whatever reason (e.g. making the code read cleaner), I'll write it in the arrow syntax instead
    If the inner fn is a one-liner, I'm more inclined to write it in arrow too regardless of what I said above, to save on the curly braces and the explicit returns

  • @User-zj2xq
    @User-zj2xq Před rokem +1

    I never used arrow functions. I mainly code JS for MediaWiki, which uses ES5 and arrow functions are a ES6 feature.

  • @d.sherman8563
    @d.sherman8563 Před rokem

    One of the issues I’ve found with using classic functions is that you can’t provide them with a type, this is used a lot in frameworks like sveltekit for typing the load functions. This looks like
    export const load: ServerLoad = (event) => { // event is typed }

  • @garikaib
    @garikaib Před rokem

    I am a Vue dev and in Vue 3 I exclusively use arrow functions. I a helper function is required at the top it's placed in a file of it's own. I prefer to group blocks based on what they do rather than just put "important" functions at the top.

  • @drrecommended4850
    @drrecommended4850 Před rokem

    KYLE THANK YOU AS ALWAYS YOU ROCK

  • @snake1625b
    @snake1625b Před rokem

    Isn't the important code usually on the bottom? With the helpers on top?

  • @ABDULMANAN-el8gr
    @ABDULMANAN-el8gr Před rokem

    WDS is the mentor we all need.

  • @matthewslyh4052
    @matthewslyh4052 Před rokem +1

    Totally agree with you on this.

  • @redsnflr
    @redsnflr Před rokem +1

    arrow functions inside functions (no "this" hoisting needed) & normal functions in the global scope is how I generally do things.

  • @Jackinua
    @Jackinua Před rokem

    Usually helpers grouped in some Object thus you will also have an error about initialization. Try to use hook document.load.

  • @DekanTrue111
    @DekanTrue111 Před rokem +1

    If I have a function, I would want to unit test it. If it is wrapped with side effects, it makes it less ideal.
    I think the problem scenario is s symptom of bad code structure

  • @harmez7
    @harmez7 Před rokem

    nice one Kyle

  • @CanRau
    @CanRau Před rokem

    Yea totally agree with all points👌 after my initial arrow function hype I moved back to normal functions in many cases

  • @rtorcato
    @rtorcato Před rokem +3

    Just put all your helpers in a file and require the file at the top. If you use the helpers often make a npm package for all your projects.

  • @joelmason6818
    @joelmason6818 Před rokem +1

    I discovered THIS the hard way during a implementation of a binary search class object. It was quite interesting.

  • @jackwaugh5768
    @jackwaugh5768 Před rokem

    It looks as though all your hoisted function names are polluting global namespace. A way to put your main work at the top and the helper functions below is to put the main code in a function and only call it after the helpers have been made available.
    I usually only use the `function` keyword when writing a method, and then, I use it as form an expression, not a "statement".

  • @ndjalopatrick6064
    @ndjalopatrick6064 Před rokem

    Please ,How to answer correctly on the quiz in a website with JavaScript ?🙏

  • @tashriser
    @tashriser Před rokem +4

    Amazing! It's nice to see an expert writing standard function syntax for the exact same reasons I also do.

  • @juliohintze595
    @juliohintze595 Před rokem +1

    I mean... if you're putting all of those helper functions in the same file as the "actual" important code, maybe the function syntax isn't the problem.
    But I agree. The "function" keyword is better to read than a const + arrow function.

  • @wisdomelue
    @wisdomelue Před rokem

    thank you

  • @Palundrium
    @Palundrium Před rokem +1

    Another reason some might prefer regular functions over arrow functions for callbacks is that you can name an anonymous regular function. Makes it a bit easier in a stack trace to quickly see the source of the error.
    Personally not for me, but I did occassionally find it useful when I had to write IE-compatible code back when callbacks were king and promises (let alone async await) weren't around yet.
    Thank god those days are gone.

    • @archmad
      @archmad Před rokem

      you do realize you can do anonymous arrow function right? (() => { })()

  • @milkdrom3da
    @milkdrom3da Před rokem

    I am so confused. I've never had a hoisting issue with arrow functions. I always have my variables up top and I mostly use arrrow funcions. Can anyone explain?

  • @jawarabanten5048
    @jawarabanten5048 Před rokem

    How to handle multiple requests at once with expressJs?

  • @Gol_D_Roger_The_Pirate_King

    You just introduced OOP thats great you are learning.

  • @nathansmith9597
    @nathansmith9597 Před rokem

    There's a mistake in the thumbnail code -- iDislikeThis should either not have the curly braces (which would cause the result of a + b to be returned implicitly) or else it needs the keyword return before a + b.