1 namespace ConsoleApplication1
 2 {
 3     class Program
 4     {
 5         static void Main(string[] args)
 6         {
 7             //場景一：找到strs集合中包含“A”的字串，然後已大寫字串和字串長度的形式轉存出來。
 8             //{Word="AS",Length=2},{Word="SPA",Length=3}
 9             //最原始的方式
10             var strs = new string[] { "
 
is", "as", "spa" };
11             List<Word> words = new List<Word>();
12             foreach (var str in strs)
13             {
14                 var upper = str.ToUpper();
15                 if (upper.Contains("A"))
16                 {
17                     words.Add(new Word() { Str = upper, Length = upper.Length });
 
18                 }
19             }
20             //現在的讀取方式
21             var query = from str in strs
22                         let upper = str.ToUpper()  //定義臨時變數
23                         where upper.Contains("A")
24                         select new { Str=upper, Length=upper.Length };
25         }
 
26     }
27     class Word
28     {
29         public string Str { get; set; }
30         public int Length { get; set; }
31     }
32 }