Question

I would like to know about regular expression and text validators using ASP.NET.
Do the tags used to control the inputs only check data client side, or is the data also checked server side?

Answer 1

You might want to check this out

http://msdn.microsoft.com/en-us/library/ms972966.aspx

It is said :

“A few things to note about the RegularExpressionValidator:

• It will never be activated by an empty string in the control it is validating. Only the RequiredFieldValidator catches empty strings
• You do not need to specify beginning of string and end of string matching characters (^ and $)—they are assumed. If you add them, it won’t hurt (or change) anything—it’s simply unnecessary.
• As with all validation controls, the validation is done client-side as well as server side. If your regular expression is not ECMAScript compliant, it will fail on the client. To avoid this, either ensure your expression is ECMAScript compliant, or set the control to perform its validation only on the server.”