docs.xsharp.it

.NET and X# permit an enhanced casting of variables. Using the casting the compiler can will check the properties and methods of the object.

local oObject as object
local oDateTime as object
	
oObject	:= DateTime.Now
oObject:AddYears( 1 ) // compiler error here
( ( DateTime ) oObject ):AddYears( 1 ) // works
oDateTime := oObject // compiler error here
oDateTime := ( DateTime ) oObject //works

The astype statement is an advanced form of casting, but if works only on datatypes that can be null:

oString := oObject asytype string

In the case that oObject is not a string, the null value is assigned to the oString variable. The following code will not work as DateTime cannot have a null value:

local oDateTime as DateTime

oDateTime := oObject astype DateTime

This code will only work if you use Nullable<DateTime> instead of DateTime