In this quick introduction, we won't look at how attributes are accessed; you can access them by name, or by iterating through them much as if they were a vector. Make sure that your code actually tests for namespace URIs, rather than assuming they are always present (or always missing).
Well, sometimes a good structured and thought out If statement can suffice, but it can become quite long and cumbersome in the future. By using Regular Expressions this way, you can reduce the chances of getting errors at erratic times. This sub checks the email's format and if it thinks that it matches, it returns True and vice versa.
Also, the more tests you are performing, the slower your app might become. For more information regarding Regular Expressions, you are welcome to look at these two MSDN articles: Because it is always easy to learn by doing things practically, you will be creating an app that makes use of Regular Expressions to determine valid input. NET application and design the form to resemble Figure 1. Obviously this only works for the formatting of the email.
Start by creating a class that extends Default Handler: method that uses the the create XMLReader method from the XMLReader Factory class to choose a SAX driver dynamically. Default Handler; public class My SAXApp extends Default Handler You can compile this code and run it (make sure you specify the SAX driver class in the sax.driver property), but nothing much will happen unless the document contains malformed XML, because you have not yet set up your application to handle SAX events.
Note the "throws Exception" wimp-out; real applications would need real error handling: We can use this object to parse XML documents, but first, we have to register event handlers that the parser can use for reporting information, using the set Content Handler and set Error Handler methods from the XMLReader interface. Things get interesting when you start implementing methods to respond to XML parsing events (remember that we registered our class to receive XML parsing events in the previous section).
Is Null Or Empty(str Phone Num) Then Phone Valid = re Phone. Text) Then 'Call Phone Validation Function Message Box. I set up my Expression to allow only numbers, but in the format I explained earlier.