VBScript : checking if the user input is an integer - vbscript

Question

Within a VBScript, I need to make sure the user inputs a integer.
Here is what I have now :
WScript.Echo "Enter an integer number : "
Number = WScript.StdIn.ReadLine
If IsNumeric(Number) Then
' Here, it still could be an integer or a floating point number
If CLng(Number) Then
WScript.Echo "Integer"
Else
WScript.Echo "Not an integer"
End If
End if
The problem is that CLng() doesn't test if my number is an integer : the number is converted anyway.
Is there a way to check if a number is an integer ?
EDIT :
The suggested answer doesn't work as well for me. Here is a new version of my code :
WScript.Echo "Enter an integer number : "
Number = WScript.StdIn.ReadLine
If IsNumeric(Number) Then
' Here, it still could be an integer or a floating point number
If Number = CLng(Number) Then
WScript.Echo "Integer"
Else
WScript.Echo "Not an integer"
End If
End if
and here is the output :
U:\>cscript //nologo test.vbs
Enter an integer number :
12
Not an integer
U:\>cscript //nologo test.vbs
Enter an integer number :
3.45
Not an integer

Answer 1

This will actually work:
WScript.Echo "Enter an integer number : "
Number = WScript.StdIn.ReadLine
If IsNumeric(Number) Then
' Here, it still could be an integer or a floating point number
If CStr(CLng(Number)) = Number Then
WScript.Echo "Integer"
Else
WScript.Echo "Not an integer"
End If
End If
Previously, the problem was that you were comparing a string vs an integer which would never evaluate to true.
Now, you take a string, check if it's numeric, transform it to CLng() which will return only the integer part of the number, transform it back to a string and finally compare it against the original string.
If you enter... "asdasD" (or any other non-numeric thing) it doesn't pass the "isNumeric" check.
If you enter "10.5" (as a string) when converted to CLng() you get 10 when then gets converted to "10" and compared against "10.5". Since the strings don't match, it says it's not an integer.
If you enter "10" converted to CLng() it's 10, back to string it's "10" which returns a true when matching it against "10", meaning it is an integer.
A few years too late I know, but I was looking into this myself just now and got puzzled by it. Hope it helps anyone else wondering around like myself.

Answer 2

This is very similar to your code:
WScript.Echo "Enter an integer number : "
Number = WScript.StdIn.ReadLine
If IsNumeric(Number) Then
' Here, it still could be an integer or a floating point number
If CLng(Number) = Number Then
WScript.Echo "Integer"
Else
WScript.Echo "Not an integer"
End If
End If

Answer 3

cogumel's answer above almost gets it, but failed for me in odd ways. I discovered that it would return true for "5" (in quotes), but not 5 (without quotes). When doing the final comparison you need to convert the original input to string as well, to make it all work reliably. Here it is wrapped in a neat function:
public function is_integer( input )
is_integer = false
If IsNumeric(input) Then
If CStr(CLng(input)) = CStr(input) Then is_integer = true
End If
end function
I've also tested this with zero (true), negative integers (true), both in and out of quote marks.

Answer 4

If you do something like this, it should work:
if Number = CInt(Number) Then

Answer 5

CLng would throw an exceprion for numbers bigger than 2147483647 or lower than -2147483648.
WScript.Echo "Enter an integer number : "
Number = WScript.StdIn.ReadLine
If IsNumeric(Number) Then
' Here, it still could be floating point number out of CLng's range
If CDbl(Number) <= 2147483647 and CDbl(Number) >= -2147483648 Then
' Here, it still could be floating point number
If CLng(Number) & "" = Number & "" Then
WScript.Echo "Integer"
Else
WScript.Echo "Not an integer"
End If
Else
WScript.Echo "Not an integer"
End If
End If

Answer 6

Here is a slightly different way to do it, it doesn’t matter if you are passing an integer, long, or a string. The function also checks if the number is a positive number, but you can change that by removing Abs().
If IsNumber("1010") Then
MsgBox "Valid whole number"
Else
MsgBox "Not a valid whole number"
End If
Function IsNumber(ByVal Number)
IsNumber = False
If IsNumeric(Number) Then
If CStr(Number) = CStr(Abs(Fix(Number))) Then
IsNumber = True
End If
End If
End Function

Answer 7

I found this simple program to validate numeric value from http://rindovincent.blogspot.com/p/vbscript-programs.html and with permission i am pasting the same. I hope it will be helpful for beginners like me
<HTML>
<HEAD><TITLE>Simple Validation</TITLE>
<SCRIPT LANGUAGE="VBScript">
<!--
Sub Submit_OnClick
Dim TheForm
Set TheForm = Document.ValidForm
If IsNumeric(TheForm.Text1.Value) Then
If TheForm.Text1.Value < 18 Or TheForm.Text1.Value > 40 Then
MsgBox "Age must be above 18"
Else
MsgBox "Thank You"
End If
Else
MsgBox "Please enter a numeric value"
End If
End Sub
-->
</SCRIPT>
</HEAD>
<BODY>
<H3>Simple Validation</H3><HR>
<FORM NAME="ValidForm">
Enter your age:
<INPUT NAME="Text1" TYPE="TEXT" SIZE="2">
<INPUT NAME="Submit" TYPE="BUTTON" VALUE="Submit">
</FORM>
</BODY>
</HTML>

Answer 8

another way,
if number > 0 then
...
end if