Class keyword - Object Creation in JavaScript P7 - Fun Fun Function

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The class keyword was added to JavaScript in ES6. On the surface, class seems to works like you’d expect, but if you look just a little closer you’ll see that class is just a thin veil on top of the existing prototypal inheritance model. In this video, I try to convince you that you should focus on learning JavaScript inheritance properly, in order to understand the mechanics of the class keyword in JavaScript.

This series is called Object Creation in JavaScript, and is meant to be a deep dive in how object creation works in JavaScript, the different ways that you can create objects and how it all fits together.

🔗 Series Playlist - Object Creation in JavaScript

🔗 Inline evaluation plugin

🔗 Composition over inheritance

🔗 The ’new’ keyword

🔗 Functional Programming in JavaScript series

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[MrRiesable]

Great video! It needed a long time to realize that inheritence is not possible in the classical sense (with private members, etc, ...). Now I have found my way out with factory functions and composition and I felt in love with javacript. You should do more videos on this topic! :)

[johnswanson]

I miss you man. Your videos are very funny and straight forward.

[slidewineder]

object creation in javascript is my favorite series on youtube

[frozen_tortus]

"Fluffykins is tiny dragon that breaths fire"
-- MPJ

[viniciusalbuquerque]

If JavaScript continue to bow down to that new people coming in, we'll have a programming language monster.

[DigitalMonsters]

Good Monday Morning, the thing I look forward to hearing every week <3

[efreitorhabibulin]

YES, the world needs more of these videos! ...not a joke and im not being sarcastic, the world actually needs more of this info out there.

[AndyRocket]

Thankyou for This video MPJ. I followed you when you made the videos. But I see now. I was not good enough to Get something out of it. This video changes the game for me. Something about the classes felt wrong. I had A problem with method overloading. And that led me in to the path Im on now. Rewriting gigantic class objects to many function and learning the nature of this beast called Javascript. Im looking forward to watch your functional programingseries🙏

[WMTeWu]

Private properties trick ? What about this:

const sound = Symbol()
export class Mammal {
constructor() {
this[sound] = "My private sound"
}
}

We can access sound property only when we have access to "sound" const. This is more like "module private" then "class private", but still.

[twfahey]

Another great video! Thanks for enlightening and entertaining me on a rainy Monday morning in Austin, TX! Really appreciate all your wisdom and insights!

[gchamaa]

Thank you for a wonderful explanation. Finally, i do feel relieved. That 'class' keyword has been really bothering me and now I'm happy to know that it's actually just a sugar keyword for basic prototypal inheritance.

[PRATIK]

I'm kind of doing the opposite. I am a JS beginner, and this idea was fed into me that classical inheritance is bad, by Medium articles by Eric Elliot (i hear he is notorious, but I have no idea if that is the case). So I really became focussed about learning prototypes well (at least it led to something fruitful, eh?), and now that I have a somewhat decent idea of it, it's still quite new for me and I don't wanna confuse myself and ruin my weeks (2 at least) of hard work by trying to understand classes in JS.

So I think I will completely avoid classes for nor, and make do with the old school of using prototypes until I am comfortable with those fully. Then I will move onto classes. So, after covering 6 of the 7 videos on this series, I will pause here, and leave without watching the last one. Hopefully, I will be back before long, when its time, and then finally watch this, and add another tool to my arsenal. Happy learning folks :3

[moistbrownypoints]

14:00 Yes. You will.

Funny comparing OOP to meth though. We make people feel less ashamed of OOP by helping them use it, then they don't feel condemned when they ask for help to get off of it. So this clean needle might still serve its purpose.

[ViniciusDallacqua]

Great episode! Whenever talking about JS 'classes' I like to illustrate how it is just really delegation on the prototype chain by screwing with 'extends'. Nothing seals the deal better :D

[vpetevotov]

Thank you for your videos and bright thinking :) You guided me to the right path!

From my experience in some situations functional style really helps to get rid of all that redundancy, which pure OOP on classes brings. When I came to Javascript, I chose Typescript dialect, because I was familiar with C# and PHP. Some solutions are really hard to implement using class inheritance even with combination of composition in context of classes, when we instantiate, then share methods. Often, even in relatively simple tasks, we need to apply OOP patterns (like "Strategy") to avoid duplication and build abstractions properly. But as the result we have huge complexity and much code to read and support. I always thought it's ok to have just one tool (I mean pure classes) to solve almost the entire range of problems, but when I came to FP paradigms I was shocked how simple and elegant solutions can be.

My personal philosophy is to use hybrid solutions, both class programming and functional approach, to get convenient solutions. The process of finding ways to do things simple and clear is very encouraging for me!

[MicahBales]

I had been reading the documentation for JS classes and just couldn't wrap my head around `super()` for some reason. Thanks for explaining it so succinctly and clearly - that super() is effectively the constructor of the inherited classes - and arguments passed into it are passed as into that constructor!

[Ellyll]

What are your thoughts on languages that compile down into JavaScript like TypeScript or CoffeeScript? (Especially as TypeScript is used for Angular now)

[eugenea]

Oh, you made me watch all series. And it was great.

[anthonypipkin]

This "clean needles" metaphor made me laugh so hard. What a great way to phrase that idea. It's almost like the committee was scheming saying "no, no come to JavaScript. It's a wonderful language. See, we even have classes". But the best part of your phrasing was aligning class inheritance to meth hahaha Best things I've heard in a while! Keep up the great work!

[YurickHauschild]

Why did you ditched the paper sheets, mpj?