OOP Principles: Composition vs Inheritance 

Have actually watched about 10 videos for composition vs inheritance this is still the best

I am having difficulties understanding this topic, but this explained far way better than the other. Great job.

Finaly some good explanation what is composition! Other videos were about rooms, walls, furniture and windows...

Thank you Dave for this video. It's the best one on this topic I've seen so far, and it helped me to understand this eventually!

I was watching different videos on this subject since last 8 hours but could not understand inheritance and composition. The approach and language used in this video is pretty simple and readily understandable.

One of the most Simple and Best explanations on this topic!!

Thanks for the video, very clear and the point. I've been using inheritance way too much over the years and this explains exactly what I've needed.

Wow I hope you make more Python and Object Oriented Design videos! This is top-notch!

Why not just separate behaviors in different classes? like barker, mover, eater cleaner and you compose every object base on behavior like.. dog will be compose of eater and barker objects, CleanRobot will be composed of cleaner object and so on.. the end game with the SuperRobot will be an object composed of barker, cleaner, mover and gameplayer. I think that would be a better, more expressive and clean design and is even more reusable because what if later on the dog needs to move too.. it would be ugly to compose a dog with a robot in order to make it move, instead of you compose dog with mover object that makes more sense!.. But nice video!

finally got the video that can explain the difference between inheritance and composition clearly , great job Mr. Dave

Provided a quick reference with some simple and easy to understand examples. Thanks a ton, helped me with my homework

You are amazing! The best video on this subject I have seen! Thank you!

Very good explanation, tried to read from many sites but this 15mn video is all you need.

Short sweet simple concise thank you. And for such simplicity one gets rewarded with alternative ideas that forget that a simple somewhat contrived example-set is needed for the original goal. I suppose as an aside for a coder to guarantee no code duplication that the objects are done away with and that all unique referenced code exists in a static function library. And then any and every object grabs an a la cart copy of what it wants to implement.

Thanks, you are the best explainer. I am not a native speaker, but there is something in your videos that is guaranteed to provide 100% absorption of information. Exactly those with a webcam.

"We need a robot that can clean, move, bark + play games..." 😂😂 That's what a boss would say

The real lesson I learned from this video is, people who create "this type of composition as explained in the video" clearly never heard about something called "abstraction".

Good video. Had to watch it at x1.5, though :)

One of the clear explanations on composition..

I've struggled for years to understand OOP, this one video has really tied it together in a FAST and EFFECTIVE way that uses examples that demonstrate the concept beautifully. Very under-rated video.

I liked this a lot. Super clear, well explained.

Thank you. I get it now. What was missing in my understanding was having functions implemented as a call-thrus to functions of member objects. I'm not sure if this'll help me on my current project, but it does give me something else to consider. Again, thanks.

I will be back here later, thank you for great explanation once again

Thanks for this awesome video. Good stuff!

You are the best teacher!

I'm not into python but coupling a bot to a dog (dependency) in order to let the bot 'bark' doesn't seem the right thing to do. Abstracting out Skills classes/interfaces as 'in between models' would make more sense and decouples bots from dogs. Both animals and bots can then have some collection of skills to be invoked.

Thanks a lot, the best video of this topic.

Excellently described!!!

Thank you so much Dave!!!

Made the concept clear. Keep it up.

Totally clear!! Thanks

Thank you! Amazing content

Amazing and simple!

Really helped me. Thanks a lot!

Well and simple described , Thank you

Amazing explanation!

Great VIdeo..How easily you explained it is awesome..Great work and Thanks for video

Thank you Soooo much!! Best explanation!!! 💙👍

Thanks for explanation!

thank you so much, this explanation is very clear

great explanation!

I want my 15 minutes back. He just literally stuffed an entire dog inside the robot so the bot can bark. Evil.

wow, i am the 10000th viewer. Great video, really helps, thank you.

Brilliant.......

great video thanks a lot

Sept 2022 - This was a fantastic example of composition. You can't believe the abstract and academic word salads that are in various texts and some other YT vids. This explained the scenario so clearly, I finally got this, and on a day I got half as much sleep as normal lol. Regarding some other comments about a better way to do this by creating new specialist classes based on the actual functions, eg, "Bark", "Move" and "Clean" class ... - they are valid points but I think Dave was explaining this from the perspective of reusing existing classes - which is often a requirement, especially if you don't own or cannot modify the code. If one could re-model the domain, I would definitely use specialist classes and then compose a new class with them. Last comment regarding the three return functions, they are not really needed as you can access them after instantiation like so "megatron.o1.move()" - Idk if this is good python form or not - just saying they can be accessed like this.

Thank you so much sir

very gooooooddddddd you are very clear

this is it folks!!

great !!!

thx so much!!!!!!!!!!!

Thanks

Very nice👍

At around 12:00, in your class of Superbot, you directly reference three of their classes in the creation of the superbot... So I'm just learning and this is the part that I'm having trouble with. I thought a class wasn't supposed to reference other classes, but that makes it super difficult to do really simple things (in my example, I've made a nuclear power plant object, that when it is created it takes a certain amount of time to "power up" and then it creates a signal, which is a reference to another class, which is a no no). Is the proper way to use some sort of interface? Any advice is appreciated.

Hi, Dave! Thank you for your video! It helped me a lot to study about inheritance and composition, but I understand the approach should be different. What about creating a class of actions and use them inside the objects as Matt suggests?

how u handle states, owned by super but reflected in sub? ex varialbe for what to woof!

I could have created a class called eater which contains that method eat, meower only with meow(), and barker with bark() only and make cat and robot cat inherit from those classes. How is composition different from multiple inheritance then?

Nice video. Just as a heads up, I don't think the return statements in the SuperBot class methods were needed.

Great video.. I noticed you did not show how you handled the duplication that was introduced by the eat() method after you converted your solution to composition, can you please tell me how to managed the duplicate eat() method in the dog and cat classes?

I dont get it , isnt that violating the SOLID principle of DIP? why don't use abstractions for Dog, Cat, CleanRobot class and use these in a constructor of main class? correct me if I am wrong please.

As i Understood, One of the benefits of using composition over inheritance is , from examples of this video , in inheritance when boss says "hey i need a SuperBot with Bark ability" , we can import whole Dog class into new SuperBot Class and its seems works ,but we are importing other abilities of Dog that we don't need them . so it may cause speed and memory problems . But in composition we just import the ability that we need. Is it true ?

Subscribed !!! I need delegation in python

I think a better implementation will have the cleaner robot class named cleaner, because all it does is clean, and it represents something that can clean. Then if you want to implement the original cleaner robot that can both clean and move, you can make a new class called CleanerRobot and have both a cleaner and a robot class in it.

awesome explanation

Sir why did you use o1, o2, o3 with superRobot? Very good video sir.

Are you monologing some well known source? I ask, because your video is almost verbatim identical to Fun Fun Function's video on the same subject from three years prior.

Wouldn't you say that the recommendation to prefer composition over inheritance is the consequence of only having single inheritance and not multiple inheritance in some defective OO languages like Java and c#? With only single inheritance, it's better not to use the feature at all in that language - instead, roll your own multiple inheritance using composition.

a pair abouts?