how to check is alphanumeric

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VB

want to check wether the string is alphanumeric or not

Posted 2-Jul-12 19:13pm

vijay bisht

Updated 25-Aug-19 1:29am

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Neetin_1809 · Answer 1 · 2014-12-09T17:54:00

Hello Vijay,
Try This
Alphanumeric is a combination of alphabetic and numeric characters.The alphanumeric character set consists of the numbers 0 to 9 and letters A to Z. for example these are the alphanumeric : Vijay1.
Dot Net Provides us the concept of Regular Expressions Under the Name Space System.Text . You Can Use Solution 1 as well.But i Intend to use RegularExpression. you can Modify Regular expression according to ur Criteria:

VB

Private Function IsAlphaNum(ByVal strInputText As String) As Boolean
      Dim IsAlpha As Boolean = False
      If System.Text.RegularExpressions.Regex.IsMatch(strInputText, "^[a-zA-Z0-9]+$") Then
          IsAlpha = True
      Else
          IsAlpha = False
      End If
      Return IsAlpha
  End Function

"^[a-zA-Z0-9]+$" is a Regular Expresiion.It Tells u a string can start from capital Characters,Small Characters Or Numbers and can contain combination of more then 1. Characters.

Prasad_Kulkarni · Answer 2 · 2012-07-02T19:40:00

Try this:

VB

Public Shared Function CheckIfAlphaNumeric(Str As String) As Boolean
 Dim IsAlpha As Boolean = True
 Dim c As Char

 Try
   For i As Integer = 0 To Str.Count - 1
   c = Str.Chars(i)
   If Not IsNumeric(c) And Not IsAlphabet(c) Then
     IsAlpha = False
   Exit For
   End If
 Next
 Catch ex As Exception
 IsAlpha = False
 End Try

Return IsAlpha
End Function

Refer more: How to check Alpha Numeric in a String[^]

Validate alphanumeric textbox[^]

2irfanshaikh · Answer 3 · 2012-07-02T19:16:00

Solution 1

i think this will help you
Convert the below code in VB.Net

C#

using System.Text.RegularExpressions;
....
....
....
private static bool CheckAlphaNumeric(string str)

{
return Regex.Match(str.Trim(), @"^[a-zA-Z0-9]*$").Success;

}

Also before asking please read MSDN or search it on search engines ...

Posted 2-Jul-12 19:16pm

2irfanshaikh

Updated 2-Jul-12 19:18pm

v3

dirigo · Answer 4 · 2014-12-09T17:04:00

Solution 3

Solution 2 is just stupid. There is no "isAlphabet" in vb.net.

Posted 9-Dec-14 17:04pm

dirigo