Null
From OpenEUO
Description
null is a unique library defined value that is employed in place of nil in certain areas. It's best to pull null into the global environment if needed to any degree. The type returned by type(null) is 'table', so a special library function, non, is used to test whether a variable's value is nil or null. If either of those values, non returns true, and false otherwise.
local sl = dofile(getinstalldir()..'/lib/simplelib.lua') null = sl.null print(type(null)) print(sl.non(null))
--> table true