Nullable Type Variable in C# Language

Introduction

A nullable type variable use to a hold null value, which provide the c# language. You can not assign a null value directly to a int type. So to make the value type accept a null value, nullable types are used. You cannot create a nullable type based on a reference type because reference types already support the null value.

Example

using System;

namespace null_coalescing_operator_in_c_sharp

{

class Program

{

static void Main(string[] args)

{

//define nullable type variable, which value is define null

int? number = null;

// is the hasvalue property which return true or false

try

{

Console.WriteLine(number.Value); //for true

}

catch(System.InvalidOperationException e)

{

Console.WriteLine(e.Message);

}

// if we have provide default value to null able type variable through GetValueOrDefault() function

number = number.GetValueOrDefault();

//then

try

{

Console.WriteLine("\nGet Default Value: {0}", number.Value); //for true

}

catch(System.InvalidOperationException e)

{

Console.WriteLine(e.Message);

}

// if we have provide a value to nullable type variable through user

number = 10;

//then

try

{

Console.WriteLine("\nGet User Value : {0}", number.Value); //for true

}

catch(System.InvalidOperationException e)

{

Console.WriteLine(e.Message);

}

Console.ReadLine();

}

Output