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The 30-Day .NET Challenge Day 15: Lazy Initialization

by Sukhpinder SinghApril 3rd, 2024

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Developers often make objects instantiated as soon as the application starts or when a class is instantiated, regardless of whether they are immediately needed or not. The.Net makes it easier to implement using Lazy<T> syntax and also safe. To unlock the full potential of your.Net Application, it’s essential to familiarize yourself with the Lazy <T> class.

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To unlock the full potential of your .Net Application, it’s essential to familiarize yourself with the Lazy<T> class.

Introduction

To enhance the power of the .Net Application, make use of the Lazy<T> class to pause the instantiation of class until the object is needed.

Learning Objectives

A common mistake of developers
How to use Lazy<T> class

Prerequisites for Developers

A basic understanding of C# language.

Getting Started

Developers common mistake

Developers often make objects instantiated as soon as the application starts or when a class is instantiated, regardless of whether they are immediately needed or not.

    // Initializing expensive resources upfront
    private readonly ExpensiveObject _expensiveObject = new ExpensiveObject();
    public ExpensiveObject ExpensiveObject => _expensiveObject;

The _expensiveObject can lead to wasted resources and reduced performance, especially if the ExpensiveObject is not used immediately or ever during the application's lifecycle.

Efficient Method

The syntax for utilizing Lazy<T> is as follows:

    // Using Lazy<T> to initialize resources only when needed
    private readonly Lazy<ExpensiveObject> _expensiveObject = new Lazy<ExpensiveObject>();
    public ExpensiveObject ExpensiveObject => _expensiveObject.Value;

The approach shifted to instantiate an object only when it needed. The .Net makes it easier to implement using Lazy<T> syntax and also safe.

Complete Example

First, let’s define an ExpensiveResource class that simulates a delay

    using System;
    using System.Threading;
    
    class ExpensiveResource
    {
        public ExpensiveResource()
        {
            Console.WriteLine("Initializing expensive resource... This might take a while.");
            // Simulating expensive initialization with a delay
            Thread.Sleep(2000); // Delay for 2 seconds
            Console.WriteLine("Expensive resource initialized!");
        }
    
        public void UseResource()
        {
            Console.WriteLine("Using the expensive resource.");
        }
    }

Now, let’s create the main part of the application, where Lazy<T> is used to initialize the ExpensiveResource lazily.

    using System;
    
    class Program
    {
        private static Lazy<ExpensiveResource> _lazyExpensiveResource = new Lazy<ExpensiveResource>();
    
        static void Main(string[] args)
        {
            Console.WriteLine("Application started.");
            Console.WriteLine("Press any key to use the expensive resource...");
            Console.ReadKey();
    
            // Accessing the Value property of _lazyExpensiveResource for the first time triggers the initialization.
            _lazyExpensiveResource.Value.UseResource();
    
            Console.WriteLine("Press any key to exit...");
            Console.ReadKey();
        }
    }