How do I use metatables

[iSyriux (Oneironaut)]

The devhub page for metatables is extremely confusing and I’m not sitting through a 30 minuted youtube commentary about metatables. I want a straight answer. How do I use metatables, what is it used for, and what can it do that regular tables can’t.

[jakebball11]

in short, metatables gives your tables the ability to have functions within tables which is mostly used when created classes with modulescripts.

[Awesom3_Eric]

There are many posts on the developer forums regarding the use of metatables. I suggest you look through these when you get a chance.

All you need to know about Metatables and Metamethods

Metatables! Truly an interesting subject. Through my activity in different forums and discord servers, I have seen many people get confused, on what they are. Main reason being, not a super wide collection of resources exist explaining them, and in general the idea of metatables is different and unique for someone who is still baby-sitted by how straight forward Luau is. I. Metatables There isn’t really a definition to what a metatable is. It’s just that, any table can have a metatable. Stick …

OLD Metatables, Metamethods, ModuleScripts and OOP

Introduction This tutorial will quickly review basic usage of tables and dictionaries and later get into metatables, and how they can be used to better your code. Pre-Requisites: Tables ModuleScripts Terminology Used Array: A collection of various data types put together and ordered using numerical keys. Example: { “Hello” , “World”, true, 27, { } } Dictionary: A collection of various data types put together using non-numerical keys. Example: {Key1 = “Nice” , EpicKey = “EPIC” , Som…

What are metatables for and how to understand them?

Metatables allow us to store metadata about data and alter the behaviour of data. Roblox only allows us to give tables a metatable. Normally, tables only have a few operations. We can associate a key with a value, get the value associated with a key, and check for strict equality between two tables. However, we cannot subtract, multiply, check if one table is less than another table, etc. Metatables allow us to add this functionality. It would be wrong to think of a metatable as something sepa…

https://devforum.roblox.com/t/why-do-people-use-metatables/605890/16
https://devforum.roblox.com/search?q=metatables

[posatta (pasta)]

@jakebball11

metatables gives your tables the ability to have functions within tables

The way this is worded makes it sound like you need a metatable to do something like {print, function() end, math.cos}. You can put a function into tables without metatables, metatables just expand the functionality of tables (e.g. allowing you to add them)

[iSyriux (Oneironaut)]

How so? What would I be able to add?

[posatta (pasta)]

Awesome’s links have more info on the specifics of how, but basically you can use metatables to define custom behavior for tables, including the ability to add them. So something like {1, 2, 3} + 4 --> {1, 2, 3, 4} could be doable if the first table had a metatable with an __add function that makes it do that. You can pretty much just define your own behavior for any operator, including stuff like table.x = y and table.x (getting and setting, which is the most common use for them).