LINQ: Combine elements in nested collection

Simple script to combine elements within nested list (A list’s elements are lists)

static void Main(string[] args)
{
  // initialize a list object with List<string> elements
  List<List<string>> nestedList = new List<List<string>>();
  // add an element to the main list object
  nestedList.Add(new List() { "a", "b", "c" });
  // add another element to the main list object  
  nestedList.Add(new List() { "d", "e", "f" });
  // LINQ query to collect all the string elements from each 
  // element within the main list. 
  // ( see equivalent foreach loop below )
  List<string> all = ( from n in nestedList
                from l in n select l).ToList();
  // print it out
  all.ForEach(new Action(delegate(string s) { Console.WriteLine(s); }));
  // output: abcdef
  Console.ReadLine();
}

The foreach loop way to combine all the elements.

// this is the traditional foreach loop for the LINQ
// query above.
foreach( List<string> n  in nestedList )
    foreach( string l in n )
        all.Add(l);

Tags: Array, LINQ