Some OOP tips you wish to share

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#1

Hello all,

This is relatively self explanatory.

I DO have some questions i would like to be answered though…
like for one,
i know that you can, for a table, do

local wowatablesocool = {}

function wowatablesocool.genericfunctionname()

but could you parent a function to an instance? like a humanoid for example? that would honestly help a lot for the self variable in functions that go like

humanoid:ChangeState()

or something.

also, i dont get the point of metatables.
like, seriously. i’ve been able to code well without them but literally everyone seems to use them, and i have no idea why. i just dont get it.
like what is the point of

local wahidk = setMetaTable({}, Mooduleee)
wahidk.__index = wahidk

what does setting the index to itself even do?!?! doesnt index mean where to look if something isnt there? i lowkey dunno why anyone would do that.

anyways, drop OOP tips in the replies. for me or anyone else who needs this.

#2

__index Metamethod Explanation
The __index metamethod is useful for classes, as whenever you want to create a new class it could index it to the metatable.

That might be confusing, but to explain it in more detail here is an example with a table using the __index metamethod.

Let’s say we create a new metatable and a table, as you can see in the example below using the __index metamethod.

local metatable = {x = 1}
local normalTable = {}

metatable.__index = metatable

setmetatable(normalTable, metatable)

Now as you can see if we try to print out the x from the normalTable it would usually print nil, but as you can see we have a metamethod, different metamethods have different uses.

print(normalTable.x)

When we print out x, it will index it and grab it from the metatable.

What is indexing?
Indexing is essentially when you access something or get something for example
normalTable.x
or
normalTable["x"]

So the __index metamethod is essentially just grabbing something from your metatable here is another example if you don’t understand.

Metatable
You: Hey can you give me “x”?
Normal Table: Sorry, I don’t have an “x”.
Normal Table: asks metatable if he has an x and if he does give it to him
Meta Table: Sure I have “x”, here you go.
Normal Table: gives you “x”

No Metatable
You: Hey can you give me “x”
Normal Table: Sorry, I don’t have an “x”

Classes
So now why do set the __index metamethod to itself?

Well, you essentially set the __index metamethod to itself because when you set it to the metatable it will know to index it to itself.

Example
Here we have a class, and it sets it’s __index metamethod to itself.

local class = {}
class.__index = class

function class.new()
	local self = {}
	setmetatable(self, class)
	
	return self
end

function class:doSomething()
	
end

return class

Why does it do this?
Well because class is a essentially just a variable with a table and it stores all of the methods, methods are functions that pass itself first as an argument.

They are contained within the class and if you have just created a new class, you can’t access them without indexing it as it would be empty.

So as you can index it the normal class will return the method.

That is why you use the __index metamethod.

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