using System;

​

public class Program

{

    public static void Main()

    {

        // Two view models

        var viewModel1 = new ViewModel()

        {

            BusinessName = "Acme",

            Address = "123 Main St"

        };

        var viewModel2 = new ViewModel()

        {

            BusinessName = "Acme",

            Address = "123 Main St Ste A"

        };

        // New application, no second view model

        Console.WriteLine(CompareViewModelProperties(viewModel1, null, vm => vm.BusinessName));

        Console.WriteLine(CompareViewModelProperties(viewModel1, null, vm => vm.Address));

        // Updated application, only address is different

        Console.WriteLine(CompareViewModelProperties(viewModel1, viewModel2, vm => vm.BusinessName));

        Console.WriteLine(CompareViewModelProperties(viewModel1, viewModel2, vm => vm.Address));

    }

​

    // Takes an anonymous function as a third parameter

    private static bool CompareViewModelProperties(ViewModel vm1, ViewModel? vm2, Func<ViewModel, string> prop)

    {

        return (vm2 != null && prop(vm1) != prop(vm2));

    }

}

​

// The view model

public class ViewModel

{

    public string BusinessName { get; set; }

    public string Address { get; set; }

}