Null-coalescing operator (??) in C#

Introduction

Null coalescing operator(??)  is one of the really great feature of C# language . This operator (??) is used to check whether object is null or not . If the object is null it provides a default value. Most of the programmer didn't use this coalescing operator in frequent programming practices.

We can say that coalescing operator (??) is used to define a default value for nullable value types or reference types. When a nullable type is assigned to a non-nullable type the ?? operator defines the default value to be returned. If a programmer try to assign  a nullable value type to a non-nullable value type and he/she not using the ?? operator then a compile time error will be generated .

Example:

using System;

namespace coalescingOperatorDemo
{
class Program
{

 static void Main()
 {

   Console.WriteLine(N);

    N = 1;

    Console.WriteLine(N);

    Console.ReadKey();

  }

public
static int? _num;

 public static int? N

  {

    get
   {
    return _num ?? 0;
    }

    set
    {
     _num = value;

       }

     }

   }

}

 

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