Convert barcode to numeric fior validation

Hi,

Panel setting: when enumerators conduct a home visit, we ask them to scan the QRcode from study participant’s user card. At that stage there should be a validation that the scanned QRcode corresponds to the preloaded hidden qrcodes in the questionnaire before starting the interview.

The issue is that the scanned QRcode produces a string variable. How can this be converted to a numeric to setup the validation rule?
Many thanks, L

Preload (into a hidden variable) the number as a string even if it is a number.

I wasn’t aware validations could be run using strings.
Many thanks!

PS: The siteresources.worldbank.org website is down for the last >3 days. It had a number of interesting pdfs, for instance a large pdf on the designer and different types of functions:
http://siteresources.worldbank.org/INTCOMPTOOLS/Resources/8213623-1380598436379/designer.pdf

Will the site get online again, or will these PDFs be made available elsewhere?

Use the following site for all the resources related to Survey Solutions:
https://support.mysurvey.solutions