Question

I have an ArrayList that contains Strings and also contains other ArrayLists which may contain Strings or even more ArrayLists.

Is there a simple way to extract all the Strings from this multilevel ArrayList?

I’m assuming some recursion is invloved but I haven’t been able to get it to work.

Answer 1

public static ArrayList FlattenList(ArrayList list) {
   ArrayList l = new ArrayList(); 
   FillList(list, l);
   return l;
}
private static void FillList(ArrayList source, ArrayList listToFill) {
   foreach (object o in source) {
      ArrayList l = o as ArrayList;
      if (l != null)
          FillList(l, listToFill);
      else
          listToFill.Add(o);
   }
}