using System;
using System.Collections.Generic;
using System.Linq;

static class TestDictionary {
    static void Main() {
        Dictionary<int, string> frenchNumbers;
        frenchNumbers = new Dictionary<int, string>();
        frenchNumbers.Add(0, "zero");
        frenchNumbers.Add(1, "one");
        frenchNumbers.Add(2, "two");
        frenchNumbers.Add(3, "three");
        frenchNumbers.Add(4, "four");

        var evenFrenchNumbers =
          from entry in frenchNumbers
          where (entry.Key % 2) == 0
          select entry.Value;
    }
}

    

   
 
using System;
using System.Linq;

static class TestArray {
    static void Main() {
        Object[] array = { "String", 12, true, 'a' };

        var types =
          array
            .Select(item => item.GetType().Name)
            .OrderBy(type => type);
    }
}

    

using System;
using System.Linq;

static class QueryReuse {
static double Square(double n) {
Console.WriteLine(“Computing Square(” + n + “)…”);
return Math.Pow(n, 2);
}

public static void Main() {
int[] numbers = { 1, 2, 3 };

var query =
from n in numbers
select Square(n);

foreach (var n in query)
Console.WriteLine(n);

for (int i = 0; i < numbers.Length; i++) numbers[i] = numbers[i] + 10; foreach (var n in query) Console.WriteLine(n); } } [/csharp]

   
 
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class Contact {
    public int Id;
    public string Name;

    public static void PublishContacts(Contact[] contacts) {
        foreach (Contact c in contacts)
            Console.WriteLine("Contact Id: {0} Contact: {1}", c.Id, c.Name);
    }
}


public class Employee {
    public int id;
    public string firstName;
    public string lastName;

    public static ArrayList GetEmployees() {
        ArrayList al = new ArrayList();
        al.Add(new Employee { id = 1, firstName = "J", lastName = "R" });
        al.Add(new Employee { id = 2, firstName = "W", lastName = "G" });
        al.Add(new Employee { id = 3, firstName = "A", lastName = "H" });
        return (al);
    }
}

public class MainClass {
    public static void Main() {
        ArrayList alEmployees = Employee.GetEmployees();
        Contact[] contacts = alEmployees
            .Cast<Employee>()
            .Select(e => new Contact {
                Id = e.id,
                Name = string.Format("{0} {1}", e.firstName, e.lastName)
            })
            .ToArray<Contact>();

        Contact.PublishContacts(contacts);

    }
}

    

   
 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class MainClass {
    public static void Main() {

        string[] words = { "b", "c", "a", "ba", "ae", "ch" };

        var wordGroups =
            from w in words
            group w by w[0] into g
            select new { FirstLetter = g.Key, Words = g };

        foreach (var g in wordGroups) {
            Console.WriteLine("Words that start with the letter '{0}':", g.FirstLetter);
            foreach (var w in g.Words) {
                Console.WriteLine(w);
            }
        }
    }
}

    

   
 

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Reflection;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
class Employee {
    int _id;
    int _idRole;
    string _lastName;
    string _firstName;

    public int ID {
        get { return _id; }
        set { _id = value; }
    }

    public int IDRole {
        get { return _idRole; }
        set { _idRole = value; }
    }

    public string LastName {
        get { return _lastName; }
        set { _lastName = value; }
    }

    public string FirstName {
        get { return _firstName; }
        set { _firstName = value; }
    }
}
class Role {
    int _id;
    string role;

    public int ID {
        get { return _id; }
        set { _id = value; }
    }

    public string Role {
        get { return role; }
        set { role = value; }
    }
}

class Program {
    static void Main(string[] args) {
        List<Employee> people = new List<Employee> {
               new Employee { ID = 1, IDRole = 1, LastName = "A", FirstName = "B"},
               new Employee { ID = 2, IDRole = 2, LastName = "G", FirstName = "T"}
            };

        List<Role> roles = new List<Role> {
              new Role  { ID = 1, Role = "Manager" },
              new Role  { ID = 2, Role = "Developer" }
            };
        var query = from p in people
                    where p.ID == 1
                    select new { p.FirstName, p.LastName };
    }
}

    

   
 
using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Reflection;

public class MainClass{
   public static void Main(){
            var q = from m in typeof(int).GetMethods()
                    orderby m.Name
                    group m by m.Name into gb
                    select new {Name = gb.Key};
   }
}