IQS

Sorting Program using C# 

In this program, just sort the numbers without using any methods..... 

To open the Console application and write the code 
namespace SortingNos 
{ 
class Program 
{ 
static void Main(string[] args) 
{ 
Console.WriteLine("Enter Numbers :"); 
int[] arr = new int[5]; 
string arr1 = ""; 
for (int i = 0; i < 5; i++) 
{ 
arr1 = Console.ReadLine(); 
arr[i] = Convert.ToInt32(arr1); 
} 

int a, b, temp = 0; 
Console.WriteLine(); 
for (a = 0; a < arr.Length; a++) 
{ 
for(b=a+1;b< arr.Length;b++) 
{ 
if (arr[a] > arr[b]) 
{ 
temp = arr[a]; 
arr[a] = arr[b]; 
arr[b] = temp; 
} 
} 
Console.WriteLine(arr[a]); 
} 
Console.ReadLine(); 
} 
} 
} 

run the program....The sample output is 

Enter Numbers : 
50 
23 
10 
4 
7 

Below are The sorted numbers 
4 
7 
10 
23 
50 

Difference between LINQ to SQL and Entity Framework

• LINQ to SQL allow you to query and modify SQL Server database by using LINQ syntax. Entity framework is a great ORM shipped by Microsoft which allow you to query and modify RDBMS like SQL Server, Oracle, DB2 and MySQL etc. by using LINQ syntax. Today, EF is widely used by each and every .NET application to query to database. The difference between LINQ to SQL and EF is given below.

LINQ to SQL

Entity Framework

It only works with SQL Server Database.

It can works with various databases like Oracle, DB2, MYSQL, SQL Server etc.

It generates a .dbml to maintain the relation

It generates an .edmx files initially. The relation is maintained using 3 different files .csdl, .msl and .ssdl

It has not support for complex type.

It has support for complex type.

It cannot generate database from model.

It can generate database from model.

It allows only one to one mapping between the entity classes and the relational tables /views.

It allows one-to-one, one-to-many & many-to-many mappings between the Entity classes and the relational tables /views

It allows you to query data using DataContext.

It allows you to query data using EntitySQL, ObjectContext, DbContext.

It provides a tightly coupled approach.

It provides a loosely coupled approach. Since its code first approach allow you to use Dependency Injection pattern which make it loosely coupled .

It can be used for rapid application development only with SQL Server.

It can be used for rapid application development with RDBMS like SQL Server, Oracle, DB2 and MySQL etc.

Singleton Design Pattern - C#

ngleton pattern falls under Creational Pattern of Gang of Four (GOF) Design Patterns in .Net. It is pattern is one of the simplest design patterns. This pattern ensures that a class has only one instance. In this article, I would like share what is Singleton pattern and how is it work?

What is Singleton Pattern?

Singleton pattern is one of the simplest design patterns. This pattern ensures that a class has only one instance and provides a global point of access to it.

Singleton Pattern - UML Diagram & Implementation

The UML class diagram for the implementation of the Singleton design pattern is given below:

The classes, and objects in the above UML class diagram are as follows:

1. Singleton

   This is a class which is responsible for creating and maintaining its own unique instance.

C# - Implementation Code

//eager initialization of singleton
public class Singleton
{
 private static Singleton instance = new Singleton();
 private Singleton() { }
 
 public static Singleton GetInstance
 {
 get
 {
 return instance;
 }
 }
}
 
////lazy initialization of singleton
public class Singleton
{
 private static Singleton instance = null;
 private Singleton() { }
 
 public static Singleton GetInstance
 {
 get
 {
 if (instance == null)
 instance = new Singleton();
 
 return instance;
 }
 }
}
 
////Thread-safe (Double-checked Locking) initialization of singleton
public class Singleton
{
 private static Singleton instance = null;
 private Singleton() { }
 private static object lockThis = new object();
 
 public static Singleton GetInstance
 {
 get
 {
 lock (lockThis)
 {
 if (instance == null)
 instance = new Singleton();
 
 return instance;
 }
 }
 }
}

Singleton Pattern - Example

Who is what?

The classes and objects in the above class diagram can be identified as follows:

1. Singleton - Singleton class

C# - Sample Code

/// <summary>
/// The 'Singleton' class
/// </summary>
public class Singleton
{
 // .NET guarantees thread safety for static initialization
 private static Singleton instance = null;
 private string Name{get;set;}
 private string IP{get;set;}
 private Singleton()
 {
 //To DO: Remove below line
 Console.WriteLine("Singleton Intance");
 
 Name = "Server1";
 IP = "192.168.1.23";
 }
 // Lock synchronization object
 private static object syncLock = new object();
 
 public static Singleton Instance
 {
 get
 {
 // Support multithreaded applications through
 // 'Double checked locking' pattern which (once
 // the instance exists) avoids locking each
 // time the method is invoked
 lock (syncLock)
 {
 if (Singleton.instance == null)
 Singleton.instance = new Singleton();
 
 return Singleton.instance;
 }
 }
 }
 
 public void Show()
 {
 Console.WriteLine("Server Information is : Name={0} & IP={1}", IP, Name);
 }
 
}
 
/// <summary>
/// Singleton Pattern Demo
/// </summary>
/// 
class Program
{
 static void Main(string[] args)
 {
 Singleton.Instance.Show();
 Singleton.Instance.Show();
 
 Console.ReadKey();
 }
}

Singleton Pattern Demo - Output

When to use it?

1. Exactly one instance of a class is required.
2. Controlled access to a single object is necessary.