I do not understand __index

[Bird_7x (XAML)]

I do not know how to use __index. I started using metatables today and I somewhat understand it. I looked everywhere on how to do this and I do not understand.

Resources:

OOP and __Index functions

So recently I have been learning OOP and it’s been going great, but I’m still learning so sorry if this is simple I’ve been reading about OOP and my main source is the All about OOP post my goal is to run a function or multiple whenever a certain stat is indexed (like changing the Level to 1) bit confused currently what I’ve been trying to do is use two of .__index but I don’t think/know if thats possible I also tried setting two metatables to the NewPet table but I don’t think thats possibl…

Metatables | Documentation - Roblox Creator Hub

All about Object Oriented Programming

ALL ABOUT OOP! Prerequisites An understanding of meta-tables (although the required code will be explained) How tables work and a competent grasp of the Lua syntax Parts What is OOP? How does it help me? How do I make this work in Lua? Integrating with module scripts What about inheritance? What is OOP? OOP stands for Object Orientated Programming and is a way of laying out code in a more friendly way whilst also keeping large projects organised. You have used objects in pro…

Creating A Furniture Placement System

This guide was originally written for scriptinghelpers . The original can be found here . One of the most common requests I get for blog post topics are for a decoration placement system that saves. I’ve shied away from this topic in the past as there is no singular “correct” way to do it. That being said, I think it’s a good exercise for all game devs to go through and will potentially place a role in a future blog post I plan to write. In addition to change things up, I’ll also take the ti…

Here is my code but I do not know what to do.

-- Module




local Class = {}
--Class.__index = Class
function Class.new()
	local self = setmetatable({},Class)
	self.Genie = "Off"
	self.__index = function(self,i)
		print("Testy") -- Not firing
		
		
		return self[i]
	end
	return self
end

return Class







-- Local Script
local Class = require(game.ReplicatedStorage.Class)
local c = Class.new()
print(c.Genie)

None of this makes sense it is just a test.
Where it says print(“Testyy”), It is not firing. How do I fix this?

[sjr04 (uep)]

self is not the metatable of anything, the a.__index = a idiom is popular in OOP so you can get the methods of the class on an instance. Not sure what you were trying to do here.