ASP N00b - How to check if a variable is set? or empty?

[helz]

hi, ive just recently started with ASP and was wondering what/if there is a way to see if a variable has been set. Either that or to check if a variable is empty?

thanks for any replies

[rdove]

You could do:

If var = "" Or IsNull(var) Then
  'Do Something
End If

[helz]

is:
var = ""
the same as:
isEmpty(var)??

[rdove]

no

var = "" is closer to IsNull(var), but not the same.

IsEmpty is completely different.

var = ""
IsEmpty(var) - returns false

and

var = Empty
IsEmpty(var) - returns true

and

Dim var
IsEmpty(var) - returns true

IsEmpty:
http://msdn.microsoft.com/library/de...fctisempty.asp

IsNull:
http://msdn.microsoft.com/library/de...sfctisnull.asp

All vbscript functions:
http://msdn.microsoft.com/library/de...ifunctions.asp