Lua Can someone explain nil to me?

[Printer]

Hiho,

Can someone explain what nil is? Example:

			local tmp = casks[itemEx.itemid]
			if(tmp == nil) then
				tmp = getFluidSourceType(itemEx.itemid)
			end

 

[leoxdnardo]

nil i think its when doesnt exist

 

[devianceone]

If you try to get a value from the table casks using a key (itemEx.itemid) that does not exist, it will return nil (nothing). You can check if something was returned by checking if the variable was set to nil or not.

 

[Joe Rod]

you are trying to set a value to a new var trying to access to a data table using itemEx.itemid as key and it doesn't exist that key in the table, so its value it becomes nil or false, you can check if exist in that table by this way

 local tmp = casks[itemEx.itemid]
			if(tmp) then
				doSomething()
			end

that means if tmp got a value when tried to access to table
Nil value means "nothing stored" as devianceone said

 

[Printer]

Thanks guys.