CODEWITHSUNDEEP
lua
ElAmoen3D
ElAmoen3D

Reputation: 11

Attempted to index "self" a nil value

I am working on a powerup class for a project and when I try to run it I get an error saying "attempted to index "self" a nil value. I would really appreciate if somebody helped me. Thanks for reading!

PS: Yes, I am using colons and not dots for my Render, Init, Update functions.


function Powerup:init()
    -- simple positional and dimensional variables
    self.x = x
    self.y = y
    self.width = 11
    self.height = 11

    
    self.dy = 0
    self.dx = 0

    self.inPlay = true
end

--[[
    Expects an argument with a bounding box, be that a paddle or a brick,
    and returns true if the bounding boxes of this and the argument overlap.
]]
function Powerup:collides(target)
    
    if self.x > target.x + target.width or target.x > self.x + self.width then
        return false
    end

    if self.y > target.y + target.height or target.y > self.y + self.height then
        return false
    end 

    
    return true
end
 
function Powerup.trigger(paddle)
    if self.inPlay then 
     self.inPlay = false
    end
end

function Powerup:update(dt)
    self.x = self.x 
    self.y = self.y + self.dy * dt

      
    if self.y <= 0 then
        self.y = 0
        self.dy = -self.dy
        gSounds['wall-hit']:play()
    end
end

function Powerup:render()
    
    if self.inPlay then
       love.graphics.draw('zucc.png', self.x, self.y)
   end
end```

Upvotes: 1

Views: 192

Answers (1)

Vinni Marcon
Vinni Marcon

Reputation: 616

table.method(self) is equal to table:method(), both are given self as the first parameter, which means that if you are using the colon :, you do not need to declare self as a parameter.

If that doesn't solve your problem, could you be more detailed and tell us exactly which line is calling for the error?

EDIT:

the reason the error is being caused is because you did not declare the variable x and y as parameters. The error is saying that "you are trying to insert the index x of self the value x, but the variable X does not exist, that is, you are trying to insert nil into the variable"

you can solve this problem by declaring the parameters in the function:

Powerup:init(x, y)

and then call the function, giving the values x and y, example:

Powerup:init(3,5)

now self.x is 3, and self.y is 5

Upvotes: 1

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