You Don't Know JS: this & Object Prototypes

Welcome to the deep dive. Today. We're going deep on JavaScript, specifically your notes on classes. We've got an excerpt here from You Don't Know Js This and Object Prototypes by Kyle Simpson.

Oh yeah, I love that book.

And it looks like you're trying to figure out this whole class thing, which even experienced developers sometimes get tripped up on.

Yeah, for sure, it can be a bit of a head scratcher.

So why don't we jump right in? The book dives right in and says JavaScript doesn't actually have.

Classes right out of the gate.

So for someone writing JavaScript code, why does this matter?

Well? I think it matters because a lot of folks come to JavaScript from other languages, okay, and they expect it to work the same way like with traditional classes and inheritance. But JavaScript has its own way of doing things. So classes in JavaScript are more of a design pattern, a way to structure your code to kind of mimic that class behavior you see in other languages.

Got it. So you're saying we're basically creating an illusion of classes exactly.

It's a bit of smoke and mirrors.

That's a really good way to put it.

To make it feel familiar.

I like that, So could you maybe give us an analogy to help visualize this concept?

Sure, thing. Let's say you have a blueprint for a house.

Okay.

This blueprint represents the class, It defines the structure, the room's the layout, you know. Yeah, but you can't actually live in the blueprint itself, right.

You can't open a door on a blueprint exactly.

You need to build an actual house based on that blueprint.

Yeah, okay, I see that. That makes a lot of sense, right, The blueprint is the plan, but the tangible house, yes, that's the object we interact with exactly. So how does JavaScript handle inheritance, right? If there aren't any real classes, Well, that's.

Where the magic of prototable inheritance comes in.

Okay.

Instead of copying behavior from parent to child classes like in traditional inheritance, okay, JavaScript uses a system of linking objects together. Each object has this internal link called prototype Okay, The points to another object.

So it's kind of like a family tree, yeah, where each person is linked to their.

Ancestors exactly, like a miniage.

An object can then access properties and methods from its ancestral objects right through this link.

Yeah, it's like a chain of linked objects. Oh wow, and this is what we call delegation. Okay, if an object doesn't have a particular property or method, it delegates the task up the chain to its prototype, okay, and so on until it finds what it needs.

So it's like a chain of command.

But for code, that's a great way to think about it.

I like that. Yeah, so this delegation concept really changes how I think about inheritings in JavaScript.

Yeah, it's a different way of thinking about it.

But if it's all about delegation, Yeah, why do we still see terms like constructor and prototype?

Hmm, that's a good question in JavaScript.

Well, I think it's part of javascripts at tem to make things you're more familiar to developers coming from those class based languages. So you have the constructor function and the prototype property. Okay, they're kind of part of this facade.

So they're trying to simulate the class like behavior but using prototypes behind the scenes.

Exactly. They're like the stage props in this illusion of classes.

So JavaScript is really putting on a show here creating this illusion of classes. It is, But the excerpt we have here argues that understanding the mechanism behind this illusion can actually help you write better code.

Absolutely, because once you see how the trick works, you can use it more effectively.

Okay, I see what you mean there. Knowing how the trick is done can help you use it better exactly. So could you give us an example of, sure how this understanding can lead to cleaner, more efficient code.

Sure. One way is through this style of coding called OLO olo. Yeah, objects linked to other objects, which Simpson really advocates for in this book.

Now sounds promising. Could you elaborate a little bit on how it actually simplifies things absolutely compared to that traditional class like approach in JavaScript.

Yeah, So let's compare them side by side. Imagine we're creating a simple object representing a car, okay, a car object. In the traditional approach, you might define a class using a constructor function, and then you'd create instances of that class using the new keyword.

Right, So that's the traditional way. Now with O low, how would that same scenario look.

Well, instead of defining a constructor okay, you would create a plane object okay that serves as the template for your car, and then you can use object dot create, object dot create to create new car objects that inherit properties and methods from that template object.

Interesting, So we're kind of side stepping that whole class illusion altogether, and we're working directly with the way that JavaScript handles objects exactly.

We're embracing the prototypal nature of the language head on. I like that.

So could we see an actual code snippet from the book sure that demonstrates this?

Yeah? Absolutely, Yeah. The book excerpt has several examples. Let's take a look at one. Great. In the traditional approach, you might define a car class like this, okay, function car make model, this make equals make this okay, model equals model.

So we're setting up the constructor function there and adding the start.

Method to its prototype exactly.

Okay, Now, how would we achieve that same functionality using OLO?

All right? So here's the OLO equivalent. Okay, constant car prototype equals and curly brace okay start colon function parentheses, curly brace okay, console dot log open parentheses quote the plus this dot make plus space plus this model plus is starting period close quote close, curly brace comma right close curly brace semicolon got it, constant my car equal object all right, create open meenthesis car prototype clothes parenthesis semicolon my car okay, make equals quote Toyota close quotes

Okay. So the difference is really striking.

It is, isn't it.

The OLO version feels so much more straightforward.

Yeah, it's much cleaner.

We're creating an object called car prototype that holds our methods right, and then using object dot create to link new car objects to this prototype. No more new keyword, no more dot prototype references.

It's all about that direct connection between objects.

I like that so much cleaner, and it really reflects the essence of JavaScript's delegation mechanism. You're explicitly defining the relationship between objects without all that extra baggage of the class syntax.

It's about cutting through the noise and getting to the heart of how JavaScript works.

This is making me rethink all my old JavaScript.

I know, right, it's a real eye opener.

But I'm curious about ES six classes.

ES six classes.

They seem to offer a cleaner syntax as.

Well, don't they They do.

They definitely look cleaner on the.

Surface, So are they the answer then.

Well, not so fast. It's important to remember that ES six classes or essentially syntactic sugar. They might look cleaner, but under the hood, they're still based on the same prototype.

System, so it's not like they're a fundamental solution. It's more like a cosmetic change.

Yeah, like a fresh code of pain on the same house.

So what are the implications of that for someone choosing between ES six classes and OLO.

Well, that's a great question, and I think the answer really depends on your priorities, Okay, and the specific project you're working on. Some developers really appreciate the familiar structure, sure and syntax that ES six classes provide. It can make the code appear more organized and potentially easier to understand.

Right, especially for those coming from class based languages.

Exactly, I feel more comfortable with that syntax.

So in some cases, the familiarity factor might outweigh the benefits of a more purist approach like OLO.

It could especially in larger teams or projects where maintaining consistency and readability are.

Crucial, right, having everyone on the same page, exactly, But there must be some downsides to using ES six class classes if they're just masking the underlying system.

Right, there are definitely some trade offs.

Does it ever lead to confusion or.

It can, particularly if developers don't understand that ESIX classes aren't true classes like in other languages, Right.

They're not really classes in the traditional sense.

They might fall into the trap of thinking in terms of traditional class inheritance, okay, and miss out on the flexibility and power right the JavaScript's prototype inheritance offers.

It's like learning a new language. You might be able to get by with basic phrases, but without understanding the grammar, you'll hit a wall when you try to express more complex ideas exactly.

And that's the risk with relying solely on the EES six class syntax okay, without grasping those core concepts of prototypes and delegation, So.

It can actually limit your understanding. It can and potentially lead to less efficient or even incorrect code.

Yeah, you might end up writing code that works but isn't really taking advantage of JavaScript strengths.

So while yes six classes might seem appealing at first glance, yeah, they don't replace the need to understand how a JavaScript actually works.

Absolutely.

What would you say are the main advantages then of embracing OLO, okay, especially for someone who's taken the time to understand prototypes and delegation well.

For one, OLO aligns perfectly with the natural flow of JavaScript, okay. It encourages you to think in terms of objects and relationships rather than forcing this concept of classes onto the language.

Right.

This can lead to more efficient and expressive code.

It sounds like OLO allows you to work with the grain of JavaScript rather than against it.

Exactly. You're working with the language of.

Strengths, and that aligns with the core principle of delegation we've been discussing, right. It's all about objects delegating tasks to one another rather than relying on this hierarchical class structure.

And that flexibility is one of JavaScript's superpowers, and OLO lets you harness that power.

So it feels like OLO is not just a different way to write code.

It's more than that, but a.

Different way to think about how objects interact in JavaScript.

It shifts your perspective from a rigid, class based mindset to a more dynamic and interconnected view of objects.

I like that, and that shift in perspective can be incredibly empowering for a JavaScript developer, it.

Opens up a whole new world of possibilities.

It's like we've been given this whole new set of lenses to view the world of JavaScript objects.

Right, and with this newfound clarity.

And with this new found clarity, we can write code that's more aligned with JavaScript's true exactly.

It's about embracing JavaScript for what it is, a powerful and flexible language built on prototypes and delegation, rather than trying to force it into this mold that doesn't quite fit.

As we wrap up this deep dive into JavaScript's classes, what's the key takeaway you would like to leave our listener with.

Hmmm, I would say experiment with both approaches. Yes, six classes in olo. See how each one feels in practice, how they impact your code structure and readability. The best choice often depends on the context, your project and your team's preferences. Makes sense, But the most important thing is to go beyond the syntax Yeah, and truly understand the underlying mechanics of JavaScript.

It's about making informed choices, not just blindly following the latest trends or syntax.

Yeah, understanding the why behind the what.

Knowledge is power, especially in this ever evolving world. Of JavaScript.

It really is. And remember whether you choose to embrace the elegance of OLO or leverage the familiarity of ES six classes. Okay, the true beauty of JavaScript lies in its dynamic nature and its ability to adapt to a wide range of programming challenges.

So there you have it. We've demystified this whole concept of classes in javascripts. He did explored the power of prototypes and delegation, and we've discovered how OLO can offer this more natural way to structure your code.

It could be a real game changer.

We hope this deep dive has given you the knowledge and the insights to really navigate the world of JavaScript objects with confidence.

I think it has.

And always remember the journey of learning and never truly ends you ever stop exploring, So keep experiment and keep exploring, and keep pushing the boundaries of what you can create with this fascinating language.

Absolutely, JavaScript is full of surprises.

Yeah, it really is like a whole new perspective.

Yeah, it's a different way of thinking about things.

On how we structure our code for sure, and how objects work in.

Javascripts can be really powerful, it can.

So as we wrap up this deep dive into JavaScript classes. Any final thoughts, I.

Guess I would just encourage everyone to keep learning. Yeah, you know, JavaScript is a language that's constantly evolving. It is, there's always something new to discover, so stay curious, keep experimenting, and never be afraid to dive deep.

That's great advice. So there you have it. Yeah, we've debunked this myth of classes in JavaScript?

Who did?

Explored this whole fascinating world of prototypes and delegation, and we've seen how OLO can really offer a more natural and efficient way to structure your code.

It's a great tool to have in your JavaScript toolbox.

And hopefully now you feel even more equipped to tackle any JavaScript challenge that comes your way.

You got this.

Thanks for joining us on this deep dive into JavaScript. My pleasure, and we'll catch you next time.