LÖVE

Posted: **Sat Oct 16, 2010 4:01 am**

hi gurus,

seeking for help on basic lua runtime error

Attempt to perform Arithmetic on Global 'my_variable'

Code

function createLandObject()

	love.graphics.print("distance " .. vecX, vecX, 10)

	temp = temp + 1
	temp = vecX
	if temp >= 300 then
		temp2 = temp
		love.graphics.print("create object " .. vecX, vecX, 20)		
		table.insert(balls, 1, {x = temp2, y = y})		
		love.graphics.draw(arrow, temp2, y)
		
		temp = 0
	end
	
end

But if i change it to below, will not have any issue

Code: Select all

function createLandObject()

	love.graphics.print("distance " .. vecX, vecX, 10)

	--temp = temp + 1
	temp = vecX
	if temp >= 300 then
		temp2 = temp
		love.graphics.print("create object " .. vecX, vecX, 20)		
		table.insert(balls, 1, {x = temp2, y = y})		
		love.graphics.draw(arrow, temp2, y)
		
		temp = 0
	end
	
end

Question
- what so different between an assignment and operation (+-*/)
- how to resolve this if i need "temp" to be increase by 1 for every call

Thanks for the help

Posted: **Sat Oct 16, 2010 4:15 am**

Where and how have you declared the temp variable?

Posted: **Sat Oct 16, 2010 4:28 am**

mikembley wrote:Where and how have you declared the temp variable?

found it!
looks like every variable need to be declare in

Code: Select all

function love.load()

end

before we use.

Posted: **Sat Oct 16, 2010 10:43 am**

weilies wrote:looks like every variable need to be declare in
Code: Select all
function love.load()

end
before we use.

Nope. You don't need to declare variables in Lua -- just make sure it has a value suitable for what you are going to do with it. (For example, if you are going to do math on it, you better make sure it points to a number or a compatible type.)

Using nil variables can make perfect sense in some contexts, just not in this one.

LÖVE

Attempt to perform Arithmetic on Global var

Attempt to perform Arithmetic on Global var

Re: Attempt to perform Arithmetic on Global var

Re: Attempt to perform Arithmetic on Global var

Re: Attempt to perform Arithmetic on Global var