string[] text ={ "Albert was here", "Burke slept late", "Connor is happy" };  var tokens = text.Select(s => s.Split(''));foreach (string[] line in tokens)foreach (string token in line)        Console.Write("{0}.", token);string[] text ={ "Albert was here", "Burke slept late", "Connor is happy" };
var tokens = text.SelectMany(s => s.Split(''));  foreach (string token in tokens)    Console.Write("{0}.", token);

class Bouquet
{public List<string> Flowers { get; set; }
}static void SelectVsSelectMany()
{List<Bouquet> bouquets = new List<Bouquet>() {new Bouquet { Flowers = new List<string> { "sunflower", "daisy", "daffodil", "larkspur" }},new Bouquet{ Flowers = new List<string> { "tulip", "rose", "orchid" }},new Bouquet{ Flowers = new List<string> { "gladiolis", "lily", "snapdragon", "aster", "protea" }},new Bouquet{ Flowers = new List<string> { "larkspur", "lilac", "iris", "dahlia" }}};// *********** Select ***********            IEnumerable<List<string>> query1 = bouquets.Select(bq => bq.Flowers);// ********* SelectMany *********IEnumerable<string> query2 = bouquets.SelectMany(bq => bq.Flowers);Console.WriteLine("Results by using Select():");// Note the extra foreach loop here.foreach (IEnumerable<String> collection in query1)foreach (string item in collection)Console.WriteLine(item);Console.WriteLine("\nResults by using SelectMany():");foreach (string item in query2)Console.WriteLine(item);/* This code produces the following output:Results by using Select():sunflowerdaisydaffodillarkspurtuliproseorchidgladiolislilysnapdragonasterprotealarkspurlilacirisdahliaResults by using SelectMany():sunflowerdaisydaffodillarkspurtuliproseorchidgladiolislilysnapdragonasterprotealarkspurlilacirisdahlia*/}

 public static IEnumerable<TResult> SelectMany<TSource, TResult>(this IEnumerable<TSource> source,                                                                        Func<TSource, IEnumerable<TResult>> selector) {if (source == null) throw Error.ArgumentNull("source");if (selector == null) throw Error.ArgumentNull("selector");return SelectManyIterator<TSource, TResult>(source, selector);}static IEnumerable<TResult> SelectManyIterator<TSource, TResult>(IEnumerable<TSource> source,                                                                        Func<TSource, IEnumerable<TResult>> selector) {foreach (TSource element in source) {foreach (TResult subElement in selector(element)) {yield return subElement;
                }}}