I have this simple application to populate fields from a data model, The data model is called “Order” which has a nested class called “Address”. When I attempt to assign a value to “Order.Address.city”, I get the error message “Object reference not set to an instance of an object.” I appreciate any help, thanks!

I tried various different ways to correct the error, Order class doesn’t seem to recognize the Address class.

Data Model is listed below….

namespace ConsoleApp1.DataModels
{
    public class Order { 
        public string name { get; set; }
        public string description { get; set; }
        public Address address { get; set; }

        
        public class Address 
        {
            public string city { get; set; }
            public string state { get; set; }
            public string zip { get; set; }
        }
    }
 }

c# code is below and error occurs when this line is executed: mtorder.address.city = “Chicago”

using ConsoleApp1.DataModels;


namespace WalmartOrderProcessing
{
    class Program
    {
         static void Main(string[] args)
        {
            Order myOrder = new Order();

            myOrder.name = "John Doe";
            myOrder.description = "Contractor";

            myOrder.address.city = "Chicago";
            myOrder.address.state = "IL";
            myOrder.address.zip = "12345";
        }
    }
}