🔧 You Don’t Know JS Yet: My Weekly Journey Through JavaScript Mastery

🕛 Zeit seit Veröffentlichung: 51 Tage, 15 Stunden 35 Minuten
📆 Veröffentlicht am: 02.03.2025 um 17:05 Uhr
Nachrichtenbereich: 🔧 Programmierung
🔗 Quelle: dev.to

Hey dev.to community!👋 I’m excited to announce a new blog post series I’ll be embarking on over the coming weeks. If you’ve ever felt like JavaScript has more layers than an onion, you’re not alone—and neither am I.

I’m diving into You Don’t Know JS Yet (Second Edition) by Kyle Simpson, and I’ll be sharing what I learn from each chapter in weekly posts right here on dev.to.

Why This Series?

JavaScript is one of the most powerful and ubiquitous (present, appearing, or found everywhere) languages in web development, but it’s also notoriously tricky to master.

I’ve been coding for a while, but there’s always more to uncover—especially with a language that evolves as quickly as JS does. You Don’t Know JS Yet is a fantastic resource for peeling back those layers, and the second edition promises fresh insights, updated for today’s JavaScript landscape (as of 2025).

This series isn’t just about me learning—it’s about us learning together. Each week, I’ll tackle a chapter from the book, take notes (yes, I’m old-school with pen and paper!), and distill the key takeaways into a blog post.

My goal? To break down complex concepts, share practical insights, and spark discussions with all of you. Whether you’re a beginner or a seasoned dev, I hope you’ll find value in this journey.

Getting Started with "Getting Started"

Let’s kick things off with the first book in the series: Getting Started. This book lays the foundation for understanding JavaScript, and my handwritten notes (scribbled on graph paper, because why not?) already have me rethinking some basics. Here’s what I’ve learned so far from the first chapter, "What is JavaScript":

JavaScript’s Quirky Origins

Did you know the name "JavaScript" was initially given to lure Java developers, but there’s almost zero similarity between the two languages? It’s a fun tidbit—and a reminder that JS has its own unique identity.

Today, JavaScript is maintained by organizations like TC39 and ECMA, who meet every other month to decide and vote on new features and review the development of current ones. TC39 proposals go through a rigorous 5-stage process (Stage 0 through 4), with members from companies like Mozilla, Apple, Google, and Samsung shaping the language’s future.

Forward-Compatible? Not Quite.

One surprising takeaway: JavaScript isn’t forward-compatible. That means any new feature added to the JS language specification won’t work in older JS engines.

For new and incompatible syntax, the solution is transpiling—converting newer JS syntax to older syntax that can run on older engines. The most popular transpiler? Babel. This process ensures modern JS code can still reach a wide audience, even on legacy systems.

Backward-Compatible, Though!

On the flip side, JS is backward-compatible. All JS code written in the past will always be valid through the future and present. This stability is a huge win for developers, ensuring our old codebases don’t break as the language evolves.

How JS Executes: A Quick Peek

JS isn’t just an interpreted language—it’s compiled, too (In the book, Kyle mentions that JS is a compiled language and proves it, but I have decided to stay out of this debate 😝).

Here’s a high-level look at the execution steps, as outlined in the book:

1. The JS code gets transpiled by tools like Babel, then bundled (often by Webpack) into a single or few files (like bundle.js). This optimizes the website to load faster, as the browser can fetch everything from one file instead of multiple.

2. The JS Virtual Machine (JS engine) executes the program, starting with an optimizing JIT (Just-In-Time) compiler.

3. The engine parses the code into an Abstract Syntax Tree (AST), then converts it into a kind of bytecode, which is further refined and optimized.

These steps highlight how modern tools and engines work together to make JS fast and flexible—a far cry from its humble beginnings!

What’s Next?

Over the next few weeks, I’ll work through each chapter of You Don’t Know JS Yet (Second Edition), starting with Getting Started and moving on to the other books in the series (as they become available—I hear the series isn’t complete yet, but I’m too excited to wait!).

You can find more about the book series on Kyle Simpson’s website or check out the GitHub repository for additional resources.

Each blog post will dive deeper into the concepts, share my aha moments, and invite your questions and insights in the comments. If you’re curious about JS, want to brush up on the fundamentals, or just enjoy a good coding journey, stick with me. Let’s explore JavaScript together—one chapter, one week, and one blog post at a time.

Stay tuned for next week’s post, where I’ll dive into the next chapter of Getting Started. In the meantime, what’s your favorite JavaScript quirk or challenge? Drop a comment—I’d love to hear from you!

Happy coding!🚀

[PS: There were many other things on topics like WebAssembly etc, that I have not covered here you can find the full chapter in YDKJSY GitHub repository]

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