Data-type testing functions

ASP constants and variables
Data-type testing functions

tbaIsArray (expression)
IsDate (expression)
IsEmpty (expression)
IsNull (expression)
IsNumeric (expression)
IsObject (expression)
VarType (expression)

The data being tested (inside the parentheses) can be any expression or variable.
These functions typically return the values True or False, although the function VarType can return any of a number of values (shown below).

Expression:A combination of variables, constants, and operators that produces a value.

0	Empty (uninitialized) variable Uninitialized [variable value]: A variable that has no value assigned to it.
1	Null (no valid data)
2	Integer
3	Long Integer
4	Single-precision floating-point number
5	Double-precision floating point number
6	Currency
7	Date
8	String
9	Automation object
10	Error
11	Boolean
12	Variant (used only with arrays of Variants)
13	Non-Automation object
17	Byte
8192	Array

XML DOM Element Type Constants 
(from file ActionPageUtil.asp): 
Constants to use as values for the CreateNode method 
of the XMLDOM. 
Constants: 

NODE_ELEMENT, NODE_ATTRIBUTE, NODE_TEXT, 
NODE_CDATA_SECTION, NODE_ENTITY_REFERENCE, NODE_ENTITY, 
NODE_PROCESSING_INSTRUCTION, NODE_COMMENT, NODE_DOCUMENT, 
NODE_DOCUMENT_TYPE, NODE_DOCUMENT_FRAGMENT, NODE_NOTATION