Object and parameter passing

Cyberience

Ok, somthing simple, language based. I have an object, with self.x and self.y inside.
I dont want to add them as paramters to the nitialisation, but can I pass the values at the initialisation stage?
like this?

MovieSprite.new("explode1",25,1,0,{x=100,y=100})

Now this doesn't work, so is there a way? or do I just create the parameters and ignore them if not used?

zvardin

No, you could either create parameters (or one table parameter and handle it) or add it to the object after.

function MovieSprite:init(str,x,y,z,attributes) for k,v in pairs(attributes) do self[k] = v end end

The best approach really depends on what you're trying to accomplish though. There is also a special param you can use "..." to mean a variable number of parameters. http://www.lua.org/pil/5.2.html

techdojo

@zvardin's approach is correct, just use one of your :init() parameters as a table and you can then pass in as little or as much as you like.

You can then use code like

function MovieSprite:init(str,x,y,z,attributes) attributes = attributes or {} local ax = attributes.x or "some default value" local ay = attributes.y or "some default value" ... ... ...   end

To automatically check (and adapt to) any parameters not being specified either via the function call OR the supplied attribute table.