C and C++ Programming Resources

[kami]

Is there a simple way or function to validate email address in ASP?

[administrator]

Code: Select all

Function IsValidEmail(emailAddress)
'Declare variables
Dim ValidEmail, emailParts, iLoopCounter, emailChar, acceptableChars
   ValidEmail = True 'set the default result to True
   'acceptableChars are the characters that we will allow in our email
   acceptableChars="abcdefghijklmnopqrstuvwxyz.-_@"
   'use the Split function to create an array with the @ as the separator
   'so if your email was test@tester.com the email would be split into an array
   'with the first array element holding "test" and the second "tester.com"
   emailParts = Split(emailAddress, "@")
   'check to make sure that there is only 1 @ and that there are 2 parts
   'remember arrays are zero based
   'Using the UBound function will return the highest element in the array
   'So if it's a valid email the UBound function will return 1, i.e. 0 start
   If UBound(emailParts) <> 1 Then
      ValidEmail = false
   Else
      'Check the length of each part of the email address
      'first part can be just one character, 2nd part must be atleast 4
      If Len(emailParts(0))<1 OR Len(emailParts(1))<4 Then
         ValidEmail = false
      End If
      'check first character on the left part isn't a "." using Left function
      If Left(emailParts(0), 1)="." Then
         ValidEmail = false
      End If
      'check the last & 2nd character from right part using Right function
      If Right(emailParts(1), 1) = "." OR Right(emailParts(1), 2) = "." Then
         ValidEmail = false
      End If
      'check that there is a . in the second part of the email address - .com
      If InStr(emailParts(1), ".") <= 0 Then
         ValidEmail = false
      End If
      'check that there shouldn't be a _ in the second part of the email address
      If InStr(emailParts(1), "_") >0 Then
         ValidEmail = false
      End If
   End If
      'loop through each character of email
   For iLoopCounter = 1 to Len(emailAddress)
   'Use Lcase & Mid functions, Mid function used to return each individual character
   'in the email, and then Lcase converts it into lowercase
   emailChar = Lcase(Mid(emailAddress, iLoopCounter, 1))
   'Check if the emailAddress characters are acceptable
      If InStr(acceptableChars, emailChar) = 0 and Not IsNumeric(emailChar) Then
         ValidEmail = false
      End if
   Next
   'check if there is 2 . in a row
   If InStr(emailAddress, "..") > 0 Then
      ValidEmail=false
   End If
   'check if there is @. in a row
   If InStr(emailAddress, "@.") > 0 Then
      ValidEmail=false
   End If
   IsValidEmail=ValidEmail
End function