Select query related in C #

Look at the code implementation:

1 using System;2 using System.Collections.Generic;3 using System.Linq;4 using System.Text;5 using System.Threading.Tasks;6 7 namespace Test8 {9 Class ProgramTen     { OneStaticvoidMain (string[] args) A         { -List<test> ListData =NewList<test>{ -                 NewTest {Name = "jiangjing", age = $, Sex = "Boy"}, the                 NewTest {Name = "wenting", age = +, Sex = "Girl"}, -                 NewTest {Name = "caihong", age = +, Sex = "Boy"}, -                 NewTest {Name = "Caiyun", age = +, Sex = "Boy"} -             }; +  -             //string[] names = {"Jiangjing", "wenting", "Caihong", "test"}; +             //1. How to use Query A             //var res = from N in Names at             //where N.endswith ("G") -             //n.substring (n.length-1) -             //select N; -  -             //2. How to use the method -             //var res = names. (N=>n). Where (N=>n.endswith ("G")); in             //foreach (var name in res) -             //Console.WriteLine (name); to  +             //3. Use of aggregation functions, analysis of large data results -             //var resultdata = Listdata.where (t=>t.age<20). Select (t=>t.age); the  *             //4. Projection: Create a new object in the query $             //var resultdata = listdata.where (t = = T.sex = "Boy"). Select (t = new {Name = T.name, age = T.age});Panax Notoginseng             //foreach (var item in Resultdata) -             //Console.WriteLine (item); the  +             //5. Single-Value selection: Distinct () function A             //var resultdata = listdata.where (t = = T.sex = "Boy"). Select (t = new {Name = T.name, age = T.age}). Distinct (); the             //foreach (var item in Resultdata) +             //Console.WriteLine (item); -  $             //6.Any and All methods $             //bool Falg1 = Resultdata.any (t=>t.name== "jiangjing"); -             //bool falg2 = resultdata.all (t = = T.name = = "Jiangjing"); -             //Console.Write ("{0} {1}", Falg1, falg2); the  -             //7. Multi-level sorting, using the method also line Orderby,thenby ..., but it's not as clear as it sounds .Wuyi             //var resultdata = from T in ListData the             //T.age, T.name -             //Select New {Name = T.name, age = t.age}; Wu             //foreach (var item in Resultdata) -             //Console.WriteLine (item); About  $             //8. Combination Query -             //var resultdata = from T in ListData -             //Group T by T.sex into TG -             //Select New {sumage = TG. Sum (t = t.age), Sex = TG. Key}; A  +             //foreach (var item in Resultdata) the             //Console.WriteLine (item); -  $             //9. Query results using the Take function or the Skip function the  the             //var resultdata = Listdata.where (t=>t.age<20); the  the             //foreach (var item in Resultdata.take (1))//take function is the first n of a result set -             //Console.WriteLine (item); in  the             //foreach (var item in Resultdata.skip (1))//skip function skips the first n of a result set the             //Console.WriteLine (item); About  the Console.readkey (); the         } the     } +  - class Test the     {Bayi Public string Name {get; set;} thePublicintAge {get; set;} the  - Public string Sex {get; set;} -  the Public override String ToString () the         { the             return"Name:" + name + "\ n" + "Age:" +Age ; the         } -     } the}

Select query related in C #