I have an alphanumeric string like sdff45hg589>@#DF456&<jk778P&&FHJ75, of which I want to extract only the numbers, without using regex or any other functions.  Dim input As String = sdff45hg589>@#DF456&<jk778P&&FHJ75Dim output As String = New String((From c As Char In input Select c Where Char.IsDigit(c)).ToArray())MsgBox(output) 'Display the output The message box will display 4558945677875.For extracting letters from the same string, I use the following: Dim input As String =  sdff45hg589>@#DF456&<jk778P&&FHJ75 Dim output As String = New String((From c As Char In input Select c Where Char.IsLetter(c)).ToArray()) MsgBox (output)Is this a better way to extract both?
Extract numbers from an AlphaNumeric string
strings;vb.net
If you want to extract both at the same time (I don't know if it is a requirement, it isn't clear in the question) you should iterate once through each character to place them in different lists.  Dim input As String = sdff45hg589>@#DF456&<jk778P&&FHJ75  Dim characters As List(Of Char) = New List(Of Char)()  Dim numbers As List(Of Char) = New List(Of Char)()  For Each c As Char In input     If (Char.IsNumber(c)) Then        numbers.Add(c)     ElseIf (Char.IsLetter(c)) Then        characters.Add(c)     End If  Next'Do whatever you have to do hereEditAs pointed out @mjolka, since the goal of the user is to show the splitted numbers and letters, a StringBuilder would be more appropriate. Here is my updated answer :   Dim input As String = sdff45hg589>@#DF456&<jk778P&&FHJ75  Dim characters As StringBuilder = New StringBuilder()  Dim numbers As StringBuilder = New StringBuilder()  For Each c As Char In input     If (Char.IsNumber(c)) Then        numbers.Append(c)     ElseIf (Char.IsLetter(c)) Then        characters.Append(c)     End If  Next'Do whatever you have to do here