Question Regarding OOP on Roblox

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#1

Hello so I have been getting into object oriented programming for a while now but am struggling to understand how to use it in my projects and also the keyword self though I am using it somehow.
To give a better understanding here is what I mean :
Please note that I am really new to this and many things or all might be wrong so please correct me.

car module
car module821Ă—191 9.92 KB

The script from where I am requiring it :
car script

my car

Note:This is a repost due to some problems
Sorry for that.

1 Like
#2

the self keyword basically just refers to the table/object that you are creating the function in. This allows you to easily change the properties/values that you have inside of the table/object. You can only use self when you use : to create a function. Ex:

local engine = {}

function engine.new()
	local self = setmetatable({}, engine)
	
	self.IsOn = false
	return self
end

function engine:ChangeEngineState()
	if self.IsOn == false then
		self.IsOn = true
	else
		self.IsOn = false
	end
end

return engine

Notice how I use : in the ChangeEngineState() function. This is so I can use self. If I did this instead:

function engine.ChangeEngineState()
	if self.IsOn == false then
		self.IsOn = true
	else
		self.IsOn = false
	end
end

The script wouldn’t know what “self” is and would throw an error. Feel free to ask any more questions!

2 Likes
#3

This is off-topic, but you can just do self.IsOn = not self.IsOn. :slightly_smiling_face:

2 Likes
#5

Not really sure what you mean by the first question, maybe try to explain it a little bit better. But for your second question yes, the way you are setting the properties in the metatable is correct. As long as it works it is correct. I personally like to define the table as “self” and set the properties from there. I believe the most standardized way to do this is how you’ve done it but to drop a line every property just to make it more readable like this:

local engine = {}

function engine.new()
	local self = setmetatable({
		IsOn = false; -- You can use , or ; here it doesn't matter I just personally use ;
		Fuel = 100;
		IsBroken = false;
		MaxSpeed = 200;
	}, engine)
	
	return self
end

return engine
1 Like