windows - How to check if a parameter (or variable) is a number in a Batch script

Question

I need to check if a parameter that is passed to a Windows Batch file is a numeric value or not. It would be good for the check to also works for variables.

I found an answer to a similar question, where the findstr command is used with a regular expression.

I did try that solution, but it’s not working like I hoped (at least on Windows?7).

My test scenarios are as follows:

AA  # not a valid number
A1  # not a valid number
1A  # not a valid number

11  # a valid number

Answer 1

SET "var="&for /f "delims=0123456789" %%i in ("%1") do set var=%%i
if defined var (echo %1 NOT numeric) else (echo %1 numeric)

Replace %1 with %yourvarname% as appropriate