//Enumerable.Range 返回起始到结束范围，是一个Enumrable<int>类型

 //Range方法并不会真的构造含有适当数字的列表，它只是在恰当的时间生成那些数，"just in time"

 var c0 = Enumerable.Range(, );

 foreach (var e in c0)

 {

     Console.WriteLine(e);//打印1,2,3,4,5,6,7,8,9,10

 }

 //Reverse()，反转列表

 var c1 = c0.Reverse();

 foreach (var e in c1)

 {

     Console.WriteLine(e);//打印10,9,8,7,6,5,4,3,2,1

 }

 //where()，过滤

 var c2 = c1.Where(x => x %  == );//返回符合谓语条件的元素，返回类型为Enumrable<int>

 foreach (var e in c2)

 {

     Console.WriteLine(e); //10,8,6,4,2

 }

 Console.WriteLine("---------------------------------------------");

 //使用链式操作，因为每个操作都是返回Enumrable<int>

 c0.Reverse().Where(x => x %  == ).ToList().ForEach(x => Console.WriteLine(x));

 //select()，进行投影，返回自定义类型对象列表

 string[] arrs = { "James", "John", "Michelle", "Amy", "Kim" };

 //返回一个匿名类型列表，该匿名类型包含First和Last属性

 var objs = arrs.Select(x => new { First = x.First(), Last = x.Last() });

 foreach (var e in objs)

 {

     Console.WriteLine(e.First); //J,J,M,A,K

     Console.WriteLine(e.Last);  //s,n,e,y,m

 }

 //选择以"J"开头的元素，将Y从首位移到未位

 var yObjs = arrs.ToList().FindAll(x => x.StartsWith("J")).Select(x =>

 {

     var y = x.Remove(, );

     return y + "J";

 });

 foreach (var e in yObjs)

 {

     Console.WriteLine(e);   //amesJ,ohnJ

 }

 //使用OrderBy进行排序,返回IOrderedEnumerable<string>

 var orderArrs = arrs.OrderBy(x => x.First());

 foreach (var e in orderArrs)

 {

     Console.WriteLine(e);   //Amy,James,John,Kim,Michelle

 }

 //ThenBy()，先使用OrderBy()以首字母排序，再以未位排序

 var thenArrs = arrs.OrderBy(x => x.First()).ThenBy(x => x.Last());

 foreach (var e in thenArrs)

 {

     Console.WriteLine(e);   //Amy,John,James,Kim,Michelle

 }