Let.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


namespace LetClause
{
    //<snippet28>
    class LetSample1
    {
        static void Main()
        {
            string[] strings = 
            {
                "A penny saved is a penny earned.",
                "The early bird catches the worm.",
                "The pen is mightier than the sword." 
            };

            // Split the sentence into an array of words
            // and select those whose first letter is a vowel.
            var earlyBirdQuery =
                from sentence in strings
                let words = sentence.Split(' ')
                from word in words
                let w = word.ToLower()
                where w[0] == 'a' || w[0] == 'e'
                    || w[0] == 'i' || w[0] == 'o'
                    || w[0] == 'u'
                select word;

            // Execute the query.
            foreach (var v in earlyBirdQuery)
            {
                Console.WriteLine("\"{0}\" starts with a vowel", v);
            }

            // Keep the console window open in debug mode.
            Console.WriteLine("Press any key to exit.");
            Console.ReadKey();
        }
    }
    /* Output:
        "A" starts with a vowel
        "is" starts with a vowel
        "a" starts with a vowel
        "earned." starts with a vowel
        "early" starts with a vowel
        "is" starts with a vowel
    */
    //</snippet28>
}