They can get ridiculously convoluted as in the case above and, according to the specification, are often too strict anyway. If you actually check the Google query I linked above, people have been writing (or trying to write) RFC-compliant regular expressions to parse email addresses for years. [email protected]%*– email’s tld is only allow character and digit 9. [email protected]– email’s last character can not end with dot “.” 11. [email protected] -email’s tld which has two characters can not contains digit Here’s a unit test using test NG. [email protected] – “.a” is not a valid tld, last tld must contains at least two characters 4. mkyong()*@– email’s is only allow character, digit, underscore and dash 8.Trying to match these restrictions is a complex task, often resulting in long regular expressions. NET Framework regular expression classes are part of the base class library and can be used with any language or tool that targets the common language runtime, including ASP. The following C# source code shows how to validate an email address with the help of regular expressions.
It’s surprisingly easy, and you’re probably already doing it anyway. If you’re going to send an activation email to users, why bother using a gigantic regular expression?After all, email offers a highly effective mode of communication, both in terms of Qo S (quality of service) and cost.Furthermore, it's asynchronous nature offers both parties the freedom of participating at a time most convenient to their time schedule.Function Valid Email(By Val str Check As String) As Boolean 'Created by Chad M. Tech Knowledgey Dim b CK As Boolean Dim str Domain Type As String Dim str Domain Name As String Const s Invalid Chars As String = "!