Using Abstract Class In C#

A few important points to  remember about an abstract class are given below.

• Abstract class cannot be directly instantiated but it can be instantiated through the base class object by type casting to it.
• Abstract class must contain at least one abstract method, which has no definition.

Now, let us see with the code snippets given below. 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//sandip patil practices
namespace AbstractclassDemo {
    class MyProgram {
        abstract class A {
            //Here show() is abstract method
            public abstract void show();
            public void disp() {
                Console.WriteLine("Display My Information");
            }
        }
        class B: A {
            public override void show() {
                Console.WriteLine("show");
            }
        }
        class Test {
            static void Main(string[] args) {
                //A a = new A(); //Not allowed
                B b = new B();
                A a = (A) b; //Allowed-> here actually you will came
                // into know how to initialize abstract class instance
                a.disp();
                Console.Read();
            }
        }
    }
}
}