CODEWITHSUNDEEP
classooplua
101010
101010

Reputation: 15756

Declaring a class in a Lua module and then instantiating it

I have a module called "MyClass.lua" It contains this:

local _S = {}

function _S:new(o)
    o = o or {}
    setmetatable(o, self)
    self.__index = self
    return o
end

return _S

In my main script, I refer to the module like this:

local c = require "MyClass"
local t = c.new()

This results in an error. It's complaining about setmetatable.

<snip>\MyClass.lua:6: bad argument #2 to 'setmetatable' (nil or table expected)

I think I'm confused about what setmetatable does, the scope of self, and the role of __index.

Upvotes: 1

Views: 453

Answers (1)

Yu Hao
Yu Hao

Reputation: 122493

The self parameter is only implicit when using the OOP style.. You need to call it like this as well:

local t = c:new()
--         ^

Upvotes: 3

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