Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Free Learning
Arrow right icon
Mastering JavaScript Variable Declarations - Insights into VAR, LET, and CONST in 2025
Mastering JavaScript Variable Declarations - Insights into VAR, LET, and CONST in 2025

Mastering JavaScript Variable Declarations - Insights into VAR, LET, and CONST in 2025: Master JavaScript Variables with VAR LET CONST and Unlock Modern Scoping and Debugging Techniques

Arrow left icon
Profile Icon SkillZone
Arrow right icon
€8.99 €82.99
Video Dec 2024 5hrs 19mins 1st Edition
Video
€8.99 €82.99
Subscription
Free Trial
Renews at €18.99p/m
Arrow left icon
Profile Icon SkillZone
Arrow right icon
€8.99 €82.99
Video Dec 2024 5hrs 19mins 1st Edition
Video
€8.99 €82.99
Subscription
Free Trial
Renews at €18.99p/m
Video
€8.99 €82.99
Subscription
Free Trial
Renews at €18.99p/m

What do you get with a video?

Product feature icon Download this video in MP4 format
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
OR
Modal Close icon
Payment Processing...
tick Completed

Billing Address

Key benefits

  • A detailed exploration of the temporal dead zone and its role in JavaScript variable behavior
  • In-depth coverage of global, function, block, and module scopes with practical insights
  • Comprehensive insights into the history and evolution of JavaScript's variable declarations

Description

Explore JavaScript like never before with an in-depth focus on variable declarations using VAR, LET, and CONST. This course starts with a historical overview, introducing foundational concepts like execution contexts, scope, and the intriguing "temporal dead zone." You'll unravel the mysteries of JavaScript's unique behaviors, from hoisting and re-declaration to the rules governing each variable type. Progressing through hands-on examples, you'll learn how JavaScript processes and executes code. Understand global and local scopes, block and module scopes, and the critical differences between lexical and dynamic scoping. Each concept is paired with real-world examples and debugging strategies to solidify your learning and enhance your coding efficiency. Conclude your journey with advanced topics such as using Object.freeze() for immutability, leveraging LET and CONST for safer, modern development, and understanding edge cases where VAR still holds relevance. Whether you're polishing your JavaScript skills or preparing for a career leap, this course equips you with the knowledge to write precise, scalable, and efficient code.

Who is this book for?

This course is designed for JavaScript developers seeking to deepen their understanding of variable declarations, scoping, and execution contexts. It is ideal for those with a foundational knowledge of JavaScript syntax and programming principles, who are ready to explore advanced concepts like the temporal dead zone, lexical environments, and modern debugging techniques. Whether you’re a front-end or back-end developer, this course will help you write cleaner, safer, and more efficient code.

What you will learn

  • Explain the lifecycle of JavaScript variables in various scopes
  • Identify differences in behavior of VAR LET and CONST effectively
  • Debug variable issues using execution context and call stack tools
  • Apply LET and CONST to write safer and more efficient JavaScript
  • Explore immutability techniques with CONST and Object.freeze
  • Compare lexical and dynamic scoping with practical examples

Product Details

Country selected
Publication date, Length, Edition, Language, ISBN-13
Publication date : Dec 23, 2024
Length: 5hrs 19mins
Edition : 1st
Language : English
ISBN-13 : 9781837024452
Category :
Languages :

What do you get with a video?

Product feature icon Download this video in MP4 format
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
OR
Modal Close icon
Payment Processing...
tick Completed

Billing Address

Product Details

Publication date : Dec 23, 2024
Length: 5hrs 19mins
Edition : 1st
Language : English
ISBN-13 : 9781837024452
Category :
Languages :

Packt Subscriptions

See our plans and pricing
Modal Close icon
€18.99 billed monthly
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Simple pricing, no contract
€189.99 billed annually
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts
€264.99 billed in 18 months
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts
Banner background image

Table of Contents

6 Chapters
Introduction Chevron down icon Chevron up icon
JavaScript's Execution Context - Creation Phase Chevron down icon Chevron up icon
JavaScript's Execution Context - Execution Phase Chevron down icon Chevron up icon
VAR, LET, CONST and BLOCKS Chevron down icon Chevron up icon
Lexical vs Dynamic Scoping Chevron down icon Chevron up icon
Outro Chevron down icon Chevron up icon
Get free access to Packt library with over 7500+ books and video courses for 7 days!
Start Free Trial

FAQs

How can I download a video package for offline viewing? Chevron down icon Chevron up icon
  1. Login to your account at Packtpub.com.
  2. Click on "My Account" and then click on the "My Videos" tab to access your videos.
  3. Click on the "Download Now" link to start your video download.
How can I extract my video file? Chevron down icon Chevron up icon

All modern operating systems ship with ZIP file extraction built in. If you'd prefer to use a dedicated compression application, we've tested WinRAR / 7-Zip for Windows, Zipeg / iZip / UnRarX for Mac and 7-Zip / PeaZip for Linux. These applications support all extension files.

How can I get help and support around my video package? Chevron down icon Chevron up icon

If your video course doesn't give you what you were expecting, either because of functionality problems or because the content isn't up to scratch, please mail customercare@packt.com with details of the problem. In addition, so that we can best provide the support you need, please include the following information for our support team.

  1. Video
  2. Format watched (HTML, MP4, streaming)
  3. Chapter or section that issue relates to (if relevant)
  4. System being played on
  5. Browser used (if relevant)
  6. Details of support
Why can’t I download my video package? Chevron down icon Chevron up icon

In the even that you are having issues downloading your video package then please follow these instructions:

  1. Disable all your browser plugins and extensions: Some security and download manager extensions can cause issues during the download.
  2. Download the video course using a different browser: We've tested downloads operate correctly in current versions of Chrome, Firefox, Internet Explorer, and Safari.