[inkey]

I have a string which i need to increment by 1.
The string layout i have is as follows "MD00494"
How would i increment this to "MD00496"
If it was a normal string witn numbers id parse it to a int. But with letters how do i do this.

[Ryano121]

.SubString the last 5 letters and the first two to get the id and the number by themselves. Then you can int.Parse the number, increment it, then add it back to the id to get your result.

[AdamSpeight2008]

I find that if you trying to increment strings, it is a sign of a bad design.

A better way is to create a class that encapsulate that functionality. You then have the option to override the .ToString function method, to return the full ID string.

Spoiler

Sorry this is vb.net code (should have looked a little closer to which forum it was). Principles remain the same though.

Public Class LetterCode
  Dim _L As String

  Private Sub New( Letters As String )
    _L = Letters
  End Sub

  Public ReadOnly Property Letters As String
    Get
      Return _L
    End Get
  End Sub

  Public Shared GetLetterCode( Letters As String ) As LetterCode
    ' Do stuff to validate letters'
    If NOT valid Then Return Nothing ' Or throw some custom exception'
    Return New LetterCode( Letters )
  End Function
End Class

Public Class ID
  Protected _Letters As Lettercode
  Protected _Numbers As Integer
  
  Public Sub New( L As LetterCode,
                  N As Integer )
  _Letters = L
  _Numbers = N
  End Sub

  Public Override Function ToString() As String
    Return String.Format( "{0}{1}", _L.ToString(), N.ToString.PadLeft( "0", 5 ) )
  End Function

  Public ReadOnly Property LetterCode
    Get
      Return _L
    End Get
  End Property

  Public ReadOnly Property Number As Integer
    Get
      Return _N
    End Get
  End Property
  
  Public Funtion IncrementNumber() As ID
    Return New ID( Me.Letters, Me.Number + 1 )
  End Sub
End Class

Now you are dealing with

This post has been edited by AdamSpeight2008: 07 March 2013 - 07:25 AM