using System;

public class Program

{

    public static void Main()

    {

        object obj = new Person { 

            FirstName = "Vijay", 

            LastName = "Kumar", 

            Address = new Address {

                City = "Chennai"

            }

        };

        //Property Pattern

        if(obj is Person { Address: {City: "Chennai" } })

            Console.WriteLine("Chennai");

        //Extended Property Pattern

        if(obj is Person { Address.City: "Chennai" })

            Console.WriteLine("Chennai");

    }

}   

​

public class Address

{

    public string City {get; set;}

}

public class Person

{

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public Address Address { get; set; }

}

​