METATABLES | What are they and how can we use them?

Поділитися
Вставка
  • Опубліковано 23 лис 2024

КОМЕНТАРІ • 97

  • @TreeLeeGames
    @TreeLeeGames 10 місяців тому +75

    meta

  • @NeverEverFaceTheDark
    @NeverEverFaceTheDark 7 місяців тому +35

    First four minutes have already done a much better job of saying what these things are than anyone else's explanation I've tried. Thanks

    • @Gix0_0
      @Gix0_0 2 місяці тому +1

      Og this is such a lifesaver nobody explains it like this. This is so simple to understand because instead of jumping to the __index then doing myTable.__index = myTable which is a ridiculously complicated syntax to understand on your first time __add just makes so much intuitive sense!

  • @nutmooose
    @nutmooose 8 місяців тому +22

    Thanks for this short and comprehensive tutorial on Metatables. You have a natural skill for teaching. I don't usually comment on youtube but I wanted to say this because I believe that we do have so many teachers but only few who has truly can do it well.

  • @Andrew90046zero
    @Andrew90046zero 10 місяців тому +26

    One thing metatables do is make it so you don't have to store functions directly inside the "instance" tables. Which means your tables only store the things that are different between each table, which saves memory.
    All of your table instances will refer to the same "metatable" for various functions and other data that is shared among all the table instances.

    • @crusherfire1
      @crusherfire1  10 місяців тому +7

      This is a great point too! Just like how you can create a single function that listens to events (for example, maybe you have dozens of UI buttons) to save on memory as well

    • @Andrew90046zero
      @Andrew90046zero 9 місяців тому +4

      ​@@crusherfire1 Thank you :D
      Idk if you plan on doing many episodes on metatables. But covering the other meta functions would definately be cool, and would compliment this video well.
      Because if somone wanted to achieve those benefits I mentioned, they would need __index and __newindex.
      Which then goes into how Lua achieves OOP.

    • @crusherfire1
      @crusherfire1  9 місяців тому +7

      @@Andrew90046zero
      I think I'll make a video in the future talking about how to use metatables for imitating OOP concepts, thanks!

  • @imaSeraphRBX
    @imaSeraphRBX 9 місяців тому +18

    Thank you for this. Ive been ignoring them for the longest time because they confused me.
    I finally get it!
    I still dont think I'll end up using them, but who knows, I may suprise myself.

    • @imaSeraphRBX
      @imaSeraphRBX 9 місяців тому

      Do you know what type of scenario would be good to implement these? They seem like fun@@epixerty

    • @TheMastrBuilder
      @TheMastrBuilder 6 місяців тому

      They are useful in OOP

  • @Jesseyn
    @Jesseyn 10 місяців тому +14

    Very Well explained video, I saw some people struggle to understand metatables so i thought it would be very difficult. But, then I saw your video and it looked so easy.

  • @SilverSuperGamer
    @SilverSuperGamer 8 місяців тому +3

    Absolutely brilliant for making those stupidly annoying to make but excellent in the end ui libraries

  • @vy_productions
    @vy_productions 20 днів тому

    Excellent video. I've been super intimidated by the apparent complexity of metatables, and this video made it super easy to understand -- it's essentially just operator overloads for tables! Nice work here.

  • @Zykdon
    @Zykdon 4 місяці тому +1

    I was scared of these for so long when watching tutorials, and now sleep deprived me just learned the entire thing in 18 minutes. VERY easy to follow video wonderful explanations keep it up man

  • @LovPotatoes
    @LovPotatoes 9 місяців тому +4

    One of the best Explanations out there! Appreciate this!

  • @Tybeef
    @Tybeef 9 місяців тому +1

    I used metatables to create an OOP without knowing what it does, but this was a great explanation of what it is.

  • @yami5007
    @yami5007 2 місяці тому

    Pretty much the best tutorial i have seen on metatables , thanks !

  • @sicknickeroni
    @sicknickeroni 9 місяців тому

    thanks! as someone who does most work in javascript and typescript, i had no previous understanding of metatables.

  • @jarrett-xr3bm
    @jarrett-xr3bm 10 місяців тому +2

    you've explained it better than anyone else, thanks!

  • @infinity2394
    @infinity2394 7 місяців тому

    YOU SIR ARE AMAZING, ONE OF THE BEST EXPLANATIONS OF METATABLES, THE ANALOGY WITH THE RESTRAUNT WAS ABSOLUTELY BRILLAINT, YOU HAVE MY UTMOST GRATITUDE! 🔥🔥

  • @hexarinumerial
    @hexarinumerial 7 місяців тому +1

    Nice video, the only thing I would've recommended is to teach the "self" syntax because that's very important in metatables

  • @diegoj4382
    @diegoj4382 26 днів тому

    This is a sort of operator overloading in R. What I don't get is the need to call table to a linkedlist(?) and call set metatable to the assignment of different methods to a list. At the end, metatabled are just classes and tables are instances

  • @taazered
    @taazered 9 місяців тому +1

    i finally understand now, true enlightenment

  • @guyguy6516
    @guyguy6516 4 місяці тому +1

    Hey man, a bit late to the party but I just discovered your channel and the way you explain things is just crazy good. Keep up the good work :) +1 sub !

  • @mafnor2268
    @mafnor2268 9 місяців тому

    Finally a tutorial on metatables I can understand, this was the only thing I never understood in lua lmao.

  • @bretabel1642
    @bretabel1642 5 місяців тому +1

    to be more specific, methods are functions that belong to objects/classes

  • @TheMastrBuilder
    @TheMastrBuilder 6 місяців тому

    Hey Cursher! Regarding the const thing, there actually is something (at least for tables) that does allow you to create readonly values. Using 'table.freeze()', we can freeze a table, making it readonly. It does not effect any tables inside it though.
    My question: How would one implement 'table.freeze()' into a system like this? Creating a whole result variable seems very round about'y', but you can't perform calculations on a read-only value.. In a nutshell, I'm trying to learn how to make code as short as possible and would like to know the pro methods. 😊

  • @SoollzPlays
    @SoollzPlays 5 місяців тому +1

    this was easier than i thought

  • @Miltonator77
    @Miltonator77 5 місяців тому +1

    Hi, I know I'm late to the party, but I have a question: In what circumstances would a metatable be more beneficial than a set of normal functions acting on a table. I am curious to the use cases behind the metatable. To me, the metatable seems more complicated to set up and limited to the pre-defined functions created by the Lua developers. I am new to Roblox Lua and programming in general and am interested in learning from an experienced programmer such as yourself. I loved this video and think you are an amazing teacher.

    • @crusherfire1
      @crusherfire1  5 місяців тому +1

      There are many metamethods for all the possible scenarios of things that can happen to your tables with the interpreter not knowing how to do them by default, so I wouldn't consider them limited.
      Metamethods won't be used commonly (I rarely use them), but the most common metamethod typically used is the __index metamethod due to its necessity for OOP.
      Another way I utilize the __index metamethod is by creating a table that errors when you index it with a key that doesn't exist. This is useful when you're trying to imitate an enum and want to make errors in your game easier to trace as the code will immediately halt instead of having a nil value floating around your code.

  • @stephen5070
    @stephen5070 5 місяців тому +1

    How can using Meta Tables help me while using Module Scripts? I'm currently making an Incremental game in Roblox Studio which will have a lot of unlockable buttons for the player to purchase. I have two choices, either hardcoding a huge wall of text to return a table or generate a bunch of keys inside a table but I have to be able remember each of the returned variables. I'm trying to manage a big player data base and make sure nothing gets out of control once my game becomes bigger.

  • @BedwarsRBLX
    @BedwarsRBLX 9 місяців тому +42

    Basically: Table on steroids

  • @amit6875
    @amit6875 9 місяців тому

    Damn thats the best explanation i have seen of metatables, great video

  • @akaisstudios
    @akaisstudios 8 місяців тому

    Good class, i'm making my own system and i'm using some of your lession to put in practice.

  • @Cidosophy
    @Cidosophy 8 місяців тому +1

    My question is which is better practice to use?
    function additionMetaTable.__add(ourTable, value)

    end
    *OR*
    local additionMetaTable = {
    __add = function(ourtable, value)
    }
    Is there any major differences? is one better practice over the other? personally I find it much easier to understand using the first way I provided

    • @crusherfire1
      @crusherfire1  8 місяців тому +2

      Either way works, just a different way to create them.
      However, it should be noted that if you need to make any functions that need to have access to the hidden 'self' keyword, it needs to be created using the colon notation.
      function SomeClass:SomeMethod()
      --- has access to self
      end
      SomeClass.SomeMethod = function()
      --- does not have access to self
      end

  • @AlexD-mg9xb
    @AlexD-mg9xb 9 місяців тому

    i aint watching allat but im liking cause crusherfire is goated

  • @jonaslavicka2411
    @jonaslavicka2411 Місяць тому

    What is a practical use of metatables? To me they seem more complicated than classes, yet less powerful

  • @SudoSed
    @SudoSed 9 місяців тому +1

    Hello, I am taking the course called Roblox studio on the Udemy platform. However, the course currently does not have a Turkish subtitle option. I have a request to add Turkish subtitles. Help me in this matter

    • @yami5007
      @yami5007 2 місяці тому

      Hala studio öğreniyor musun

  • @polymerr
    @polymerr 5 місяців тому

    is there anyway you can post your roblox studio script editor theme? it's really nice to the eyes (ok never mind, I found it)

  • @arandom_bwplayeralt
    @arandom_bwplayeralt Місяць тому

    holy shet i actually might need string interpolation

  • @EpicPico0625
    @EpicPico0625 9 місяців тому +1

    Essentially tables with modifiable behavior

  • @the_chosen_one1235
    @the_chosen_one1235 10 місяців тому

    make a FastCast tutorial please and also a tutorial about ViewportFrames 💖💖

    • @crusherfire1
      @crusherfire1  9 місяців тому +1

      I actually have not yet found a need to use the FastCast module.
      However, you don't need to wait for me to learn it, I'd recommend reading the documentation for FastCast and experimenting with it yourself!
      etithespir.it/FastCastAPIDocs/
      As for ViewportFrames, maybe?! 🤔

  • @Yusaq
    @Yusaq 9 місяців тому

    thanks

  • @RexBruhh
    @RexBruhh 8 місяців тому

    Whenever I try to print something out I get as output table: 0x79d1391f852dbe5e

  • @betapacket
    @betapacket 10 місяців тому +1

    did anyone tell him that using pairs or ipairs is redundant because you can just pass the table in the for loop (for x, y in ipairsOrPairs(z) -> for x, y in z)

    • @crusherfire1
      @crusherfire1  10 місяців тому +16

      Yes, I know you can pass a table directly without the use of an iterator like ipairs() or pairs(). This is a feature exclusive to Luau and not native Lua.
      However, if you do not use an iterator and pass the table itself and if that table has a metatable with a custom __call metamethod, that __call metamethod will be executed, which may not be desired behavior. Wrapping in ipairs() or pairs() prevents that issue.

    • @xwewfbgcangvao6159
      @xwewfbgcangvao6159 5 місяців тому +1

      @@crusherfire1thx

  • @o_master362
    @o_master362 4 місяці тому

    Metatables are also great ways for exploiters to hook onto your functions ;)

  • @mightymixsal
    @mightymixsal 3 місяці тому

    So it's like a module script but for tables

    • @GuizinPE81
      @GuizinPE81 2 місяці тому

      Modules are tables generally

  • @PumpyGT
    @PumpyGT Місяць тому

    metable

  • @yourcomputerhasdied
    @yourcomputerhasdied 9 місяців тому

    I loove metatables 🤤

  • @Andrew90046zero
    @Andrew90046zero 10 місяців тому +1

    table

  • @rfo.
    @rfo. 9 місяців тому

    Thx

  • @noturne54
    @noturne54 6 місяців тому

    I never ever saw any real utility to the metamethods except __index and __newindex other than making tables fancier. Maybe organization? Its not the best for it, so it seems kinda pointless tho.

    • @nxsus
      @nxsus 5 місяців тому

      __eq

  • @tal5667
    @tal5667 8 місяців тому

    what's your studio colours? looks sick

    • @crusherfire1
      @crusherfire1  8 місяців тому

      you can check out this plugin for some neat code editor color schemes:
      create.roblox.com/store/asset/3617323299

  • @JeffaFloppa
    @JeffaFloppa 9 місяців тому +1

    now we need oop...

  • @seeray11
    @seeray11 2 місяці тому

    0-0:8. That’s my story…

  • @crooda3681
    @crooda3681 4 місяці тому

    table with workers

  • @Schwert_Brawl_Stars
    @Schwert_Brawl_Stars 10 місяців тому

    Have you a dc server?

  • @bbnmm8720
    @bbnmm8720 9 місяців тому +1

    1:37 what is the music tell me now or your next code will give a error 😈😈

    • @crusherfire1
      @crusherfire1  9 місяців тому

      oh no!
      the music for this video can be found here:
      ua-cam.com/video/muLrR10nThM/v-deo.html

    • @bbnmm8720
      @bbnmm8720 9 місяців тому

      In a distant kingdom where bytes danced to algorithmic melodies and codes wove the fabric of the digital universe, a young programmer found themselves ensnared in the clutches of a dreadful curse: the dreaded "Fatal Error". This error cast a shadow over their work, bringing forth despair and frustration. Try as they might, they couldn't unravel the origins of this mysterious error.
      In their distress, they sought help. They made their way to the tower of the wise code master, an old and sage programmer known as Master Algorithmos. The tower was shrouded in digital mist, and with hope in their heart, they knocked on the door.
      Master Algorithmos, with their long beard and white hair, welcomed them kindly. With a wise smile, they said, "Ah, young one, I see the cloak of the 'Fatal Error' has enveloped you. But fear not, for every error has its solution, and every problem, its answer."
      Seated at a table laden with code manuscripts, Master Algorithmos guided them through the intricate pathways of the algorithm, unveiling hidden secrets and invisible patterns. With patience and wisdom, they explored lines of code, debugged functions, and unraveled the enigmas of programmatic logic.
      As the hours passed and the stars danced in the digital sky, they felt a weight being lifted off their shoulders. The "Fatal Error" began to lose its grip on them. Thanks to the guidance of Master Algorithmos, they began to see the light at the end of the programming tunnel.
      Finally, after a journey of learning and discovery, they found the solution to the "Fatal Error". With a simple adjustment to the code, the curse was broken, and the project came back to life, shimmering with newfound energy.
      In gratitude to the wise code master, they thanked Master Algorithmos with humility and respect. They vowed to honor the knowledge gained and share it with other programmers, so that they would never again succumb to the power of the "Fatal Error".
      And so, with a light heart and a renewed mind, they returned to their work, ready to face new challenges with courage and determination. For now they knew that, with the right guidance and the will to learn, no programming error could stand in their way. And thus, the legend of the one who broke free from the curse of the "Fatal Error" spread throughout the kingdom, inspiring programmers everywhere to never give up, no matter how daunting the code.@@crusherfire1

    • @bbnmm8720
      @bbnmm8720 9 місяців тому

      @@crusherfire1 i meant... thanks you wont get any error, will use this song for programming rn

  • @ralphwuu
    @ralphwuu 9 місяців тому

    Similar to Python dunder methods

    • @crusherfire1
      @crusherfire1  9 місяців тому +1

      Yup, and metatables allow us to imitate classes! You can actually recreate many Roblox classes, like Vector3, entirely from tables and metatables!

  • @xvqwer
    @xvqwer Місяць тому

    Now we know where Metamethod and Metatableindex got their names from lol