C#中的let字句应用示例

using System;
using System.Linq;

namespace UseLet
{
 class Program
 {
 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."
  };

  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;

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

  Console.WriteLine("Press any key to exit");
  Console.ReadLine();
 }
 }
}