VBScript runtime error '800a01a8' when an empty string comes to [duplicate] - vbscript

Question

What is the quickest and easiest way (in Classic ASP) to check if a string has some string (that has a length greater than 0) i.e. NOT "Null", "Nothing", "Empty", or '' empty string

Answer 1

To make sure that the Variant you deal with is of sub-type "string", you need the VarType or TypeName function. To rule out zero length strings, you need Len(). To guard against strings of space, you could throw in a Trim().
Code to illustrate/experiment with:
Option Explicit
Function qq(s) : qq = """" & s & """" : End Function
Function toLiteral(x)
Select Case VarType(x)
Case vbEmpty
toLiteral = "<Empty>"
Case vbNull
toLiteral = "<Null>"
Case vbObject
toLiteral = "<" & TypeName(x) & " object>"
Case vbString
toLiteral = qq(x)
Case Else
toLiteral = CStr(x)
End Select
End Function
Function isGoodStr(x)
isGoodStr = False
If vbString = VarType(x) Then
If 0 < Len(x) Then
isGoodStr = True
End If
End If
End Function
Dim x
For Each x In Array("ok", "", " ", 1, 1.1, True, Null, Empty, New RegExp)
WScript.Echo toLiteral(x), CStr(isGoodStr(x))
Next
output:
cscript 26107006.vbs
"ok" True
"" False
" " True
1 False
1.1 False
True False
<Null> False
<Empty> False
<IRegExp2 object> False

Answer 2

Here's a one-liner that dodges all the trouble with Null by concatenating the value with an empty string. It works for Null, Empty, "", and, of course, strings with actual length! The only one it doesn't (nor shouldn't) work for is Nothing, because that's for object variables, of which a string is not.
isNullOrEmpty = (Len("" & myString) = 0)

Answer 3

You could try having something like this:
Function nz(valToCheck, valIfNull)
If IsNull(valToCheck) then
nz = valIfNull
Else
nz = valToCheck
End if
End function
and then you would use it like this:
if nz(var,"") <> "" then
'--string has something in it
else
'--string is null or empty
end is

Answer 4

You can use the VarType() function to check if it is a string, then you can check if the string is not empty. This statement will only pass through a string that isn't empty.
If VarType(MyString) = 8 Then
If MyString <> "" Then
'String is Not Null And Not Empty, code goes here
End If
End If

Answer 5

This worked for me:
if mystring = "" then wscript.echo "Empty string"
else wscript.echo "String is not empty"

Answer 6

<%
Dim x,y
x = "abcdefg"
'counting length of string
y = Len(x)
Response.Write (y)
'checking string is empty or not
If Len(x) = 0 then
Response.Write ("<p>String is empty</p>")
Else
Response.Write ("<p>String is not empty</p>")
End If
%>
Hope this is helpful.