Remove duplicate strings - C#
 Here is the code     1 2 3  var  words = new  HashSet(); string  text = "praveen kumar thalluri praveen kumar thalluri" ; text = Regex.Replace(text, "\\w+" , m => words.Add(m.Value.ToUpperInvariant())? m.Value: String.Empty);      Courtesy: http://stackoverflow.com/questions/1058783/regular-expression-to-find-and-remove-duplicate-words