Csharp/CSharp Tutorial/LINQ/var

An Anonymous Type Assigned to a Variable Declared with the var Keyword

<source lang="csharp">using System; public class MainClass {

   public static void Main() {
       var unnamedTypeVar = new { firstArg = 1, secondArg = "Joe" };
       Console.WriteLine(unnamedTypeVar.firstArg + ". " + unnamedTypeVar.secondArg);
   }

}</source>

An Example of Collection Initialization

<source lang="csharp">using System.Collections.Generic; using System; public class MainClass {

   public static void Main() {
       List<string> presidents = new List<string> { "AAAA", "BBBBBB", "CCCCCCCC" };
       foreach (string president in presidents) {
           Console.WriteLine(president);
       }
   }

}</source>

Explicit Range Variable

<source lang="csharp">using System; using System.Collections; using System.Linq; using System.ruponentModel;

   class MainClass
   {
       static void Main()
       {
           ArrayList list = new ArrayList { "First", "Second", "Third" };
           var strings = from string entry in list
                         select entry.Substring(0, 3);

           foreach (string start in strings)
           {
               Console.WriteLine(start);
           }
       }
   }</source>

Instantiating and Initializing an Anonymous Type Using Object Initialization

<source lang="csharp">using System; public class MainClass {

   public static void Main() {
       var address = new {
           address = "First Street",
           city = "Vancouver",
           state = "GA",
           postalCode = "99999"
       };
       Console.WriteLine("address = {0} : city = {1} : state = {2} : zip = {3}",
        address.address, address.city, address.state, address.postalCode);
       Console.WriteLine("{0}", address.GetType().ToString());
   }

}</source>

Reflecting result from Linq

<source lang="csharp">using System; using System.Collections.Generic; using System.Text; using System.Xml.Linq; using System.Linq;

   class Program
   {
       static void Main(string[] args)
       {
           string[] currentVideoGames = {"q", "2", 
                                 "this is a test", "aaa",
                                 "eee", "System"};
           var subset = from game in currentVideoGames 
                                where game.Length > 6
                                orderby game
                                select game;
           foreach (var s in subset)
               Console.WriteLine("Item: {0}", s);
           Console.WriteLine("resultSet is of type: {0}", subset.GetType().Name);
           Console.WriteLine("resultSet location: {0}", subset.GetType().Assembly);
       
       }
   }</source>

Using var

<source lang="csharp">using System; using System.Collections.Generic; using System.Diagnostics; class MyPC {

   public Int32 Id { get; set; }
   public Int64 Memory { get; set; }
   public String Name { get; set; }

} class LanguageFeatures {

   static void Main(string[] args) {
       var processes = new List<MyPC>();
       foreach (var process in Process.GetProcesses()) {
           var data = new MyPC();
           data.Id = process.Id;
           data.Name = process.ProcessName;
           data.Memory = process.WorkingSet64;
           processes.Add(data);
       }
       Console.Write(processes);
   }

}</source>