Lazy Loading Techniques in C# dotnet core.

LazyLoadingDemo.cs

using System;
using System.Diagnostics;

namespace LazyLoadingExample
{
    public class MyPreferences
    {
        private Widget myWidget = null;

        public Widget GetMyWidgetObject(int widgetId)
        {
            myWidget = new Widget(widgetId);
            return myWidget;
        }

        public Widget MyWidget => myWidget;        
    }

    public class MyPreferencesLazyLoad
    {
        private readonly Lazy<Widget> myLazyWidgetObj;

        //default constructor
        public MyPreferencesLazyLoad()=> myLazyWidgetObj = new Lazy<Widget>();        
        
        //parameterized constructor.
        public MyPreferencesLazyLoad(int widgetId) => myLazyWidgetObj = new Lazy<Widget>(() => new Widget(widgetId));        

        public bool IsWidgetObjectCreated
        {
            get
            {
                if (myLazyWidgetObj != null)
                {
                    return myLazyWidgetObj.IsValueCreated;
                }
                else
                {
                    return false;
                }
            }
        }

        public Widget MyWidget => myLazyWidgetObj?.Value;        
    }

    public class Widget
    {
        private int _widgetId;
        public Widget() { }
        public Widget(int id) => _widgetId = id;
        public void SetWidgetId(int widgetId) => _widgetId = widgetId;        
        public int GetWidgetId() => _widgetId;
    }

    class Program
    {
        const int _maxLoppingNumber = 100000;
        static void Main(string[] args)
        {
            var s1 = Stopwatch.StartNew();
            var myPreferences = new MyPreferences();
            Console.WriteLine("---------------------Start 1st Loop Type-----------------------");
            Console.WriteLine("-------------Version 1: Lazy Loading old classic way--------------");
            Console.WriteLine();

            for (int i = 0; i < _maxLoppingNumber; i++)
            {
                var widget = myPreferences.GetMyWidgetObject(i);

                //print on every ten thousand loop
                if ((i / 10000) >= 1 && (i % 10000) == 0)
                {
                    Console.WriteLine("Instance Count  :- {0}", widget.GetWidgetId());
                }
            }
            s1.Stop();

            var lazyLoadMyPreferences = new MyPreferencesLazyLoad();
            Console.WriteLine();            
            Console.WriteLine("Lazy object benefit");            
            Console.WriteLine("Lazy Widget Object created : {0}", lazyLoadMyPreferences.IsWidgetObjectCreated);
            Console.WriteLine("WidgetId to be created: {0}",lazyLoadMyPreferences.MyWidget.GetWidgetId());
            Console.WriteLine("Lazy Widget Object created : {0}", lazyLoadMyPreferences.IsWidgetObjectCreated);
            Console.WriteLine();

            // Version 2: create Lazy every time in loop, and access Value each time.
            var s2 = Stopwatch.StartNew();
            Console.WriteLine("-------Start 2nd Loop Type- Creating Lazy Loading object fresh in each iteration------");
            Console.WriteLine();
            for (int i = 0; i < _maxLoppingNumber; i++)
            {
                var objMyPreferences = new MyPreferencesLazyLoad(i);

                //print on every ten thousand loop
                if ((i / 10000) >= 1 && (i % 10000) == 0)
                {
                    Console.WriteLine("Instance Count  :- {0}", objMyPreferences.MyWidget.GetWidgetId());
                }
            }
            s2.Stop();
            Console.WriteLine();

            // Version 3 : create lazy object once , and access Value each time in loop.
            var s3 = Stopwatch.StartNew();
            Console.WriteLine("------Start 3rd Loop Type- Creating Lazy Loading object once, access Value in each iteration------");
            Console.WriteLine();

            var objPreferences = new MyPreferencesLazyLoad();
            for (int i = 0; i < _maxLoppingNumber; i++)
            {
                objPreferences.MyWidget.SetWidgetId(i);

                //print on every ten thousand loop
                if ((i / 10000) >= 1 && (i % 10000) == 0)
                {
                    Console.WriteLine("Instance Count  :- {0}", objPreferences.MyWidget.GetWidgetId());
                }
            }
            s3.Stop();

            Console.WriteLine();
            Console.WriteLine("=======RESULTS BENCHMARKED=======");
            Console.WriteLine();
            Console.WriteLine("performance for Classic Lazy Loading Approach: {0}", ((double)(s1.Elapsed.TotalMilliseconds * 1000000) / _maxLoppingNumber).ToString("0.00 ns"));
            Console.WriteLine("performance after Lazy loading object creation in every iteration: {0}", ((double)(s2.Elapsed.TotalMilliseconds * 1000000) / _maxLoppingNumber).ToString("0.00 ns"));
            Console.WriteLine("performance after reusing lazy loading object created once: {0}", ((double)(s3.Elapsed.TotalMilliseconds * 1000000) / _maxLoppingNumber).ToString("0.00 ns"));
            Console.ReadLine();

        }
    }
}