how to create regular expression based on some condition RSS

• • Reply
  

  kalkal

  Member

  18 Points

  11 Posts

  how to create regular expression based on some condition

  May 02, 2012 08:36 PM|LINK

  Hi,

  i want to create a regular expression to find and replace uppercase character based on some condition.
  Find the starting uppercase for a group of uppercase character in a string and replace it lowercase and "*" before the starting uppercase.
  If there is any lowercase following the uppercase,replace the uppercase with lowercase and "*" before the starting uppercase.
  
  input string : stackOVERFlow
  
  expected output : stack*over*flow
  
  i tried but could not get it working perfectly.
  
  Any idea on how to create a regular expression ?
  Thanks

   

• • Reply
  

  Paul Linton

  Star

  13431 Points

  2535 Posts

  Re: how to create regular expression based on some condition

  May 02, 2012 11:41 PM|LINK

  I don't do regular expressions but Linq is quite up to the challange

  string x = "stackOVERFlow";
  
  var y = x.ToCharArray()
           .Skip(1)
           .Select((c,pos) =>
                      ((char.IsLower(x[pos]) && char.IsUpper(x[pos+1])) ||  //lower to upper
                       (char.IsUpper(x[pos+1]) && x.Length>pos+1 && char.IsLower(x[pos+2])) // upper to lower
                                 ? "*"
                                 : string.Empty
                      )
                      + char.ToLower(x[pos+1]))
           .Aggregate (x.Substring(0,1), (sofar,c) =>  sofar+c );

  Got a c# problem? Try .NET Book Zero from Charles Petzold, it's a free pdf.
  • Marked as answer by Allen Li - MSFT on May 08, 2012 01:49 AM