Program:

The source code to demonstrate the unboxing in C# is given below. The given program is compiled and executed successfully on Microsoft Visual Studio.

//Program to demonstrate the unboxing in C#

using System;

class UnBoxDemo
{
    int intVar;
    void Unbox(object Ob)
    {
        intVar= (int)Ob;
    }
    object Box(int val)
    {
        intVar = 0;
        return (object)val;
    }
    public static void Main()
    {
        UnBoxDemo D = new UnBoxDemo();
        object ObVal=10;

        D.Unbox(ObVal);
        Console.WriteLine("intVar : "+D.intVar);

        ObVal = D.Box(20);

        Console.WriteLine("ObVal : "+ObVal);
    }
}

Output:

intVar : 10
ObVal : 20
Press any key to continue . . .

Explanation:

In the above program, we created a class UnBoxDemo that contains a data member intVar of integer type, and we also created two methods Box() and UnBox() that performs boxing and un-boxing respectively. 

In the Main() method, we created the object D of UnBoxDemo class and then perform Unboxing and Boxing and print the values on the console screen.