Nullable Data Type in C#

C# - Nullables

C# provides a special data types, the nullable types, to which you can assign normal range of values as well as null values.

For example, you can store any value from -2,147,483,648 to 2,147,483,647 or null in a Nullable< Int32 > variable. Similarly, you can assign true, false or null in a Nullable< bool > variable. Syntax for declaring a nullable type is as follows:

< data_type> ? <variable_name> = null;

The following example demonstrates use of nullable data types:

using System;

namespace CalculatorApplication

{

class NullablesAtShow

{

static void Main(string[] args)

{

int? num1 = null;

int? num2 = 45;

double? num3 = new double?();

double? num4 = 3.14157;

bool? boolval = new bool?();

// display the values

Console.WriteLine("Nullables at Show: {0}, {1}, {2}, {3}",

num1, num2, num3, num4);

Console.WriteLine("A Nullable boolean value: {0}", boolval);

Console.ReadLine();