How do I check if some user input is an integer?

Hi there

I'm making a CMS, and each page is referenced by ID. For instance, a URL might be:

www.mydomain.com/index.asp?p=142

Code (markup):

Now, it is possible to type in:

www.mydomain.com/index.asp?p=abc

Code (markup):

and you get a big ugly error because the ID field in my database is an autonumber, so there are no delimiters, and the field doesn't accept text. Anyone know how to check if Request.Querystring("p") is an integer?

Thanks in advance

Dylan

 

Try this if you use VB.Net, else convert to C#:

Dim theString As String = Request.Querystring("p")

If IsNumeric(theString) Then
Do Something
Else
Do Something Else
End If

 

Thanks, that fixed it

 

IsNumeric(123.45) = True

if you really careful, check Int(vInt) = vInt

 

I know you already got an answer, however if you want to stick to classic ASP, the following should work:

theVariable = Request.Querystring("p")
If theVariable + 1 > 0 Then
' This is a number
Else
' It would have returned -1, and we know that it's not a number
End If

 

The IsNumeric() function is in classic ASP

 

IsNumeric(request("input"))

this will return true of false.

 

Yup, that's what I wanted