Probably the most useful 10 min of learning OOP so far. I never really understood those 4 principles and now they seem a) sorta easy (both to use and memorize) and b) I was already applying some of them without knowing. Amazing! Thank you kindly
OOP was THE hot topic when I was a developer. Took me a little study to understand its foundational concepts. I couldn’t understand why everyone seemed to think that it was THE way to create programs. Sanity eventually prevailed, as it usually does, and it certainly has its place, but if your design does not utilize inheritance and polymorphism, then use another language type. Don’t force a particular model into an OOP design just because your CompSci instructor loved Java.
I learned OOP from a video that Philippe Kahn made about the subject when Borland’s Turbo Pascal first introduced this new way of programming. It took awhile to understand and master the concepts, but after that, I absolutely loved it and it made large, complicated projects so much more manageable. The ability to start with a base class and do inheritance was extremely powerful. It literally enabled us to program our products in a fraction of the time and with fewer programmers than the old spaghetti code ways of coding.
I agree. It's a great way to manage large projects. I worked for a number of years in software development (albeit as an educator) and OOP allowed hundreds of developers, in different parts of the world, with a range of skills, to work together effectively on very complex applications. :)KD
Finally a concise and clear explanation about these fundamentals. The amount of interchangeable terms (that still have different meaning(s) under certain context's) is ridiculous - and near impossible to find a video/documentation that explains them without convolution.
I'm very very impressed. I'm not a strict Java begineer, but I did need to find videos/resources to understand these OOP concepts better. I had watched already 5-10 sources, but yours is just the most clear. Concise, and clear. Very impressive. Thanks!
You had a very clear and nice way to describe those concepts. But in my opinion, Polymorphism is much more than just the ability to override a method from a super class. Polymorphism is the ability of an object to take on many forms. Thanks for a great video
You welcome. Polymorphism catches a lot of people out - so I wanted to keep it very simple for now. One day I will come up with some other examples which make the point that it does indeed literally mean 'many forms' :)KD
Yes. The video leads one to believe that polymorphism is only used in subclasses to override superclass methods. Duck typing (not always available, depends on the language) is the more general and useful case where the same message name can be used in classes that have no common superclass.
This is a new concept fo me and I've watched about a dozen of videos but should have started with this one. The clarity and simplicity of the explanation are unmatched. Thank you!
You haven't been to the moon, yet. If you should ever try OOP in reality you will be disappointed though. It does not do any of the things it promises well. The problem lies in the fact that data dependencies in real world applications have a graph structure (a tree, if you are lucky). OOP is not very good at taking care of that and if you try to use inheritance, in particular, then you will find that you are hard-coding assumptions about that data dependency that may change during the evolution of your project, which will make frequent refactoring necessary. There are better ways of dealing with that problem. Try to learn to think about programs as state machines with as few distinct states as possible. Rather than encapsulating data, control state change. Each state change should be associated with a well defined change of the data. That way your data structures can change freely as the project matures, but the basic flow of the program (as seen by both the user and the programmer) stays the same.
I am delighted to help. You will hear a lot of negativity about OOP but please bear in mind that it aims to facilitate collaboration and scalability. :)KD
Thank you so much, this was very helpful! My professor and textbook did such a poor job of explaining these basics that I felt like I was falling behind.
Thank you, I have watched this video about 5 times over the last week, every time... I grasp the concept you are talking about a little more, and then understand another smaller detail you mention. I really, really like that whilst explaining, you animate very clear, sensible, logical examples as you go, so I can see what you mean as you are explaining it. I still need to watch it many more times fully, but it is clever, logical, makes sense and is super interesting. Thank you for taking all the time to put this together.. your time a few years ago, has helped nearly half a million people... or if like me.. helped 100k people 5x. ha ha
Wow this is the best explanation Ive seen!!! I have atechnical interview tomorrow and I only know data and sql and not much about OOP in debt. THANK YOU for this great educational content. Today they always jump to Python or the programming name directly, but I miss the real theory and thinking.
Will add to the pile of positive comments here and say this is the most concise, informative, and accessible video on the subject I've seen. great work
The part on inheritance has some potential theoretical issues, but it is after all just an introduction. Generally speaking, inheritance should be used to model "is a special kind of" relationship, and should not be used to model as "is a role played by a" relationship. An employee is not a special type of person, it is a role played by a person. Same goes for Customer: that is not a special type of person, it is a role played by a person. For example, Alice could be an Employee of Walmart, but she could also shop there so could also be a Customer of Walmart. So if you are creating an object for Alice, would you create an instance of Employee or Customer? On the other hand, a dog "is a special kind of" animal, not a role played by an animal; and a fish "is a special kind of animal", not a role played by an animal. A dog cannot simultaneously be a fish, nor can a dog quit being a dog and become a fish; and a fish cannot simultaneously be a dog, nor can a fish quite being a fish and become a dog. So here inheritance does not suffer from the above problem. If you have a pet dog named Wolfy or Max, there is no ambiguity in what class you would use to create an instance for your pet: it would be a dog.
I see what you mean. However, the context of the system you are designing is important. If for example I was building a payroll system, and Alice was an employee, it is probably neither here nor there if she is also a customer (staff discounts excepted). :)KD
this has been the best video i have ever seen - great analogies and loved how you included all the different terms used to describe the same thing - new sub
I have seen many as I keep forgetting it but this stands out. Thank you for the creators and the presenter such a clarity and use of just enough visuals. Esp the take away is synonyms which are used, that trips me, After this hopefully not anymore.
Great breakdown/explanation of the OOP concept. OOP is one of my favorite areas in computer science/programming applications. Its not as an intimidating as it sounds. Next: I would love to see a short video on the application of these four OOP constructs in terms of their application; write a simple program that demonstrates each of the four areas. Thanks.
i wish i watched this at the start of my OOP subject, the way you explained it made it so much easier to understand, the examples you used and visual effects really helped also. edit: I also remember watching your Dijkstra's Shortest path video back in highschool, that was also amazing.
5:51 "An Employee is *also* a person" The way this is said with such a straight face, I thought it was a set up for a joke, like: "An Employee is *also* a person, unless they work at a Law-Firm."
Great job! Thanks for saying what a class is really. The word template was close to meaningless to me. But saying that a class is "code written by a programmer" is far more precise and meaningful to me.
I once was doing telephone interviews for senior developer positions at SAGE (the accounting software company). I asked the candidate if he could give me an explanation of what polymorphism was and an example of where he’d used it. He accused me of making the term up 🤔. “What the bloody hell is that” or words to that effect. He didn’t get invited to a face to face interview.
Hmm... now terms encapsulation and API seem to be the same or at least very similar.. would you agree? Encapsulation is usually used when we talk about OOP, and API is usually used more broadly - not explicitly connected with OOP. You also mentioned data hiding, another term that is usually mixed with encapsulation. All I'm saying is that there are very similar terms that are connected with each other. Anyway, beautiful video. One of the greatest channels. Thanks for creating this content for free!
Thank you, and you are most welcome. I can see where you're coming from. An API is a way that a programmer can utilise the code someone else has written without being able to see 'under the bonnet'. In that sense, the API code is encapsulated. The most used definition of encapsulation is "the hiding of data and complexity", but it is also a way that an organisation can protect their intellectual property, that is, their source code. Many people confuse encapsulation with abstraction. Abstraction is to "ignore detail". If you are a studying for an exam and might get asked questions about OOP, then the definitions are important.
@@ComputerScienceLessons OOP provides abstraction, all right, but it provides the wrong abstraction for the overwhelming majority of problems because the "functions act mostly on data inside their own class" assumption is usually not even remotely correct. As soon as there are strong dependencies between data elements in different classes (and there almost always are), OOP becomes an unsolvable puzzle.
Thank you for your brilliant explaination. I now know why OOP does not work for my type of programming. I deal with mathematical processes and not objects. Data goes in, formulas are applied, results come out, results are stored or presented. OOP fits database problems. My programming fit the chsos of a spreadsheet.
"An employee of a business is also a person" - that's a bold statement right there
That's what I keep telling myself! :)KD
exactly ! very outlandish .
😂😂
For real 🤣
🤣🤣🤯
The clearest and simplest explanation of OOP I've ever seen. Many thanks.
You're very welcome. Thank you :)KD
Any one who has the OOSAD project?
Absolutely brilliant. Simple, clear, concise. The whole concept in my mind started as a soft blur and sharpened to crystal clarity.
A lot of BS actually, the author didn't pay attention to correct definitions. But useful to find out common misconceptions.
why is it BS?@@trevoro.9731
The clarity and simplicity is unparalleled.
Thank you :)KD
So you're saying it's serial? Since it's not parallel
@@SithLord2066 lame.
@@notyournormaldev1419 I'll be here all week
I'm a university professor myself, and I have to say that is the most crystal clear, explanation I've ever seen for computer science concepts.
Delighted to help. Thank you :)KD
Remarkable. Remarkable simplicity, clarity, and conciseness. Transformed my vague understanding into clarity without overwhelming me. Thank you!
You are most welcome. Thanks for the lovely comment :)KD
Probably the most useful 10 min of learning OOP so far. I never really understood those 4 principles and now they seem a) sorta easy (both to use and memorize) and b) I was already applying some of them without knowing. Amazing! Thank you kindly
OOP was THE hot topic when I was a developer. Took me a little study to understand its foundational concepts. I couldn’t understand why everyone seemed to think that it was THE way to create programs. Sanity eventually prevailed, as it usually does, and it certainly has its place, but if your design does not utilize inheritance and polymorphism, then use another language type. Don’t force a particular model into an OOP design just because your CompSci instructor loved Java.
You can do (real) OOP in C, and do it better than in Java.
This video is the most helpful and concise one I 've ever seen so far among those about the fundamental terms and concepts. Thanks a lot!
This was a very clear and in-depth explanation. Thank you!
Thank you. Much appreciated :)KD
I have finally found a concise, 1 line definition of polymorphism. Thank you very much, big thumbs up.
better would be "A subclass can morph / change an inherited method"
I learned OOP from a video that Philippe Kahn made about the subject when Borland’s Turbo Pascal first introduced this new way of programming. It took awhile to understand and master the concepts, but after that, I absolutely loved it and it made large, complicated projects so much more manageable. The ability to start with a base class and do inheritance was extremely powerful. It literally enabled us to program our products in a fraction of the time and with fewer programmers than the old spaghetti code ways of coding.
I agree. It's a great way to manage large projects. I worked for a number of years in software development (albeit as an educator) and OOP allowed hundreds of developers, in different parts of the world, with a range of skills, to work together effectively on very complex applications. :)KD
Wow - sometimes the algorithm really does turn up 'gems'. Many many thanks!! As a visual learner this 'gem' is invaluable.
You're very kind. Thanks for the comment. :)KD
Finally a concise and clear explanation about these fundamentals.
The amount of interchangeable terms (that still have different meaning(s) under certain context's) is ridiculous - and near impossible to find a video/documentation that explains them without convolution.
I'm a great believer in keeping things as simple as possible. Delighted to help. :)KD
This channel is actually phenomenal it needs to be more popular
You are very kind :)KD
I'm very very impressed. I'm not a strict Java begineer, but I did need to find videos/resources to understand these OOP concepts better. I had watched already 5-10 sources, but yours is just the most clear. Concise, and clear. Very impressive. Thanks!
You are very welcome and thank you :)KD
I keep coming back to this video. The OOP concepts are well explained in simplest and clearest way.
Delighted to help :)KD
The clearest and simplest explanation of OOP. Thanks!
You're welcome :)KD
This is excellent. Very clear and precise. I'm going to re-watch it a couple of times to really drive the concepts home.
Always good to get a refresher on what OOP is.
You had a very clear and nice way to describe those concepts. But in my opinion, Polymorphism is much more than just the ability to override a method from a super class. Polymorphism is the ability of an object to take on many forms. Thanks for a great video
You welcome. Polymorphism catches a lot of people out - so I wanted to keep it very simple for now. One day I will come up with some other examples which make the point that it does indeed literally mean 'many forms' :)KD
Yes. The video leads one to believe that polymorphism is only used in subclasses to override superclass methods. Duck typing (not always available, depends on the language) is the more general and useful case where the same message name can be used in classes that have no common superclass.
Life saving explanation, better than having to sit through a 2 hour video to understand it. Brilliant!
This is such a good channel for understanding computer science concepts, honestly just the best. Thank you!
This was a very clear and understandable video. Thanks for that man.
This channel needs more attention
Wow. Someone who could explain inheritance in an intuitive way. It actually makes a lot of sense.
This is a new concept fo me and I've watched about a dozen of videos but should have started with this one. The clarity and simplicity of the explanation are unmatched. Thank you!
You are most welcome, and thank you :)KD
One of the few golden channels on UA-cam.
You're very kind. Thanks :)KD
Hats off, sir. Thanks a lot for making this well-documented video about OOP.
You are very welcome :)KD
This video needs more views! Great explanation of OOP.
Thank you :)KD
I have spent several weeks trying to understand the professor till I found this 9 min video. Now I feel like I've been to the moon an back.
You haven't been to the moon, yet. If you should ever try OOP in reality you will be disappointed though. It does not do any of the things it promises well. The problem lies in the fact that data dependencies in real world applications have a graph structure (a tree, if you are lucky). OOP is not very good at taking care of that and if you try to use inheritance, in particular, then you will find that you are hard-coding assumptions about that data dependency that may change during the evolution of your project, which will make frequent refactoring necessary. There are better ways of dealing with that problem. Try to learn to think about programs as state machines with as few distinct states as possible. Rather than encapsulating data, control state change. Each state change should be associated with a well defined change of the data. That way your data structures can change freely as the project matures, but the basic flow of the program (as seen by both the user and the programmer) stays the same.
I am delighted to help. You will hear a lot of negativity about OOP but please bear in mind that it aims to facilitate collaboration and scalability. :)KD
@@ComputerScienceLessons What are you helping with here by distributing your ignorance about proper software engineering? ;-)
Thank you so much, this was very helpful! My professor and textbook did such a poor job of explaining these basics that I felt like I was falling behind.
You are most welcome. Glad to help :)KD
If you sped up this video, then you are not worthy of the uploaders precious time. Thank you for the top notch explanation
Thank you :)KD
The clearest and simplest explanation of OOP I've ever seen. Many thanks. (2)
You're very welcome. Thank you :)KD
Thank you, I have watched this video about 5 times over the last week, every time... I grasp the concept you are talking about a little more, and then understand another smaller detail you mention.
I really, really like that whilst explaining, you animate very clear, sensible, logical examples as you go, so I can see what you mean as you are explaining it.
I still need to watch it many more times fully, but it is clever, logical, makes sense and is super interesting. Thank you for taking all the time to put this together.. your time a few years ago, has helped nearly half a million people... or if like me.. helped 100k people 5x. ha ha
You are very welcome, and thank you :)KD
excellent, could have never understood it so clearly in 9 minutes.
Wow this is the best explanation Ive seen!!! I have atechnical interview tomorrow and I only know data and sql and not much about OOP in debt. THANK YOU for this great educational content. Today they always jump to Python or the programming name directly, but I miss the real theory and thinking.
You are most welcome. I hope it all went well. Good luck :)KD
Will add to the pile of positive comments here and say this is the most concise, informative, and accessible video on the subject I've seen. great work
This is one of the best explanations that I have come across as a new learner it's very well explained
Thank you :)KD
This was the best explanation I have ever came across! great job and thanks for the video
You are most welcome :)KD
I'm so glad I found this channel, i was just thinking i should get more into programming in my free time. thanks it was super easy to follow!
You are most welcome :)KD
Wonderfully explained! Have not found a better explanation anywhere online!!!
Thank you so much. :)KD
The part on inheritance has some potential theoretical issues, but it is after all just an introduction. Generally speaking, inheritance should be used to model "is a special kind of" relationship, and should not be used to model as "is a role played by a" relationship. An employee is not a special type of person, it is a role played by a person. Same goes for Customer: that is not a special type of person, it is a role played by a person. For example, Alice could be an Employee of Walmart, but she could also shop there so could also be a Customer of Walmart. So if you are creating an object for Alice, would you create an instance of Employee or Customer?
On the other hand, a dog "is a special kind of" animal, not a role played by an animal; and a fish "is a special kind of animal", not a role played by an animal. A dog cannot simultaneously be a fish, nor can a dog quit being a dog and become a fish; and a fish cannot simultaneously be a dog, nor can a fish quite being a fish and become a dog. So here inheritance does not suffer from the above problem. If you have a pet dog named Wolfy or Max, there is no ambiguity in what class you would use to create an instance for your pet: it would be a dog.
I see what you mean. However, the context of the system you are designing is important. If for example I was building a payroll system, and Alice was an employee, it is probably neither here nor there if she is also a customer (staff discounts excepted). :)KD
very clear, concise , precise and comprehensive video on OOP.
thank you for the effort!
You are very welcome - and thank you :)KD
Best OOP explanation, simple and straight forward
Thank you :)KD
this has been the best video i have ever seen - great analogies and loved how you included all the different terms used to describe the same thing - new sub
Thank you :)KD
I have seen many as I keep forgetting it but this stands out. Thank you for the creators and the presenter such a clarity and use of just enough visuals. Esp the take away is synonyms which are used, that trips me, After this hopefully not anymore.
You are most welcome. :)KD
The best video explains class and object instance creation in such best way (using graphical representation ).loved that 🤩
You are most welcome :)KD
SUCH a good video! Thank you. I wonder why it took me so long to find this channel.
Thank you so much :)KD
Great breakdown/explanation of the OOP concept. OOP is one of my favorite areas in computer science/programming applications. Its not as an intimidating as it sounds. Next: I would love to see a short video on the application of these four OOP constructs in terms of their application; write a simple program that demonstrates each of the four areas. Thanks.
wow I ve been searching for this video the whole day !!! perfectly explained !
Surprisingly clear and succinct, thanks for clearing this up 🤝.
Please do keep up the good work 🙂.
You are most welcome and thank you :)KD
It's been said, I know, but you're a really great instructor. Hope (for others) that you do this for a living.
Thanks.This is the best OO explanation ever.
You're very welcome. And thank you so much :)KD
i wish i watched this at the start of my OOP subject, the way you explained it made it so much easier to understand, the examples you used and visual effects really helped also.
edit: I also remember watching your Dijkstra's Shortest path video back in highschool, that was also amazing.
That's great to here. Thanks for commenting. :)KD
Thanks so much for a great video !
Helps us to relate and thus makes learning "enjoyable"
Learning programming is my current "hobby".
Thanks again !
You are most welcome :)KD If you enjoy programming - have you seen my video on how to make a GeoGuessr type game? :)KD
Closest thing to understand Database management system
*Now* I understand polymorphism. Thank you!
You're welcome :)KD
5:51 "An Employee is *also* a person"
The way this is said with such a straight face, I thought it was a set up for a joke, like:
"An Employee is *also* a person, unless they work at a Law-Firm."
This is so clean and simple, yet informative, thank you so much, please keep uploading!
ur videos r so simple and informative man
Thanks for saying so :)KD
Very clear explanation of the basics of OOP. Thank you.
Thank you :)KD
Big W. You sir, are brilliant. Just look at how many people are heaping praise and all well-deserved. Thank you!
You are very kind. Thank you. :)KD
Simple and straight forward. Thanks a lot!
You're welcome, and thank you :)KD
Amazing explanation. Good job!
Thank you :)KD
I picked a book on OOP 25 odd years back ... TODAY i understood the fundamentals LOL LOL ... thanks for the video ♥♥
Delegated to help, albeit a little late. You are most welcome. :)KD
As clear as crystal. Thank you!
You are very welcome :)KD
Great job!
Thanks for saying what a class is really. The word template was close to meaningless to me. But saying that a class is "code written by a programmer" is far more precise and meaningful to me.
Definitely th best explanation ever. Subscribed.
Thank you :)KD
This video is mad with super clear and simplistic yet uber effective explaination. xD
Thank you :)KD
The entire series is really really good! very well explained. Thanks a lot
Thank you for your explaination. I've learnt quite a lot from watching your video. Keep up the good work in teaching beginners like me.
Thank you :)KD
Probably the best and easiest explanation. Thank you.
Many experienced programmers even the very good ones can't really explain Polymorphism clearly! Thanks :)
You are very welcome :)KD
I once was doing telephone interviews for senior developer positions at SAGE (the accounting software company).
I asked the candidate if he could give me an explanation of what polymorphism was and an example of where he’d used it.
He accused me of making the term up 🤔. “What the bloody hell is that” or words to that effect.
He didn’t get invited to a face to face interview.
10/10 in explaining OOP concepts.
What an amazing crystal clear explanation, got confused in university
Thank so much you :)KD
Damn, this was awesome! Like…I know these concepts, but now…I somehow know them better.
Thank you :)KD
Oh god, now I get polymorphism... Thank for the explanation 👍
You're welcome :)KD
Best video I have seen till now. Attained full conceptual clarity
Thank you for teaching these basic pillars of OOP
You are most welcome :)KD
Such Brevity and Clarity !!
Very concise and accurate. Most helpful, thanks.
Really upping the animation quality, very nice sir!
Thanks for noticing. I was playing around with a very old version of Adobe Flash :)KD
Amazingly succinct, clear and thorough!
massively useful definitions of OOP terminology - thanks!
You're very welcome :)KD
This is a super clear way of defining and demonstrating the concepts ! infinite Thanks ❤🔥
You are very welcome :)KD
This is a great video! My teacher shared it with us to revise the concepts we are learning currently in school!
Thank you so much. I'll be on the curriculum next. :)KD
Top tier explination, relevant terminology is incoporated adequately
Thank you :)KD
this is one of the best explanations i have seen thank you
Hmm... now terms encapsulation and API seem to be the same or at least very similar.. would you agree?
Encapsulation is usually used when we talk about OOP, and API is usually used more broadly - not explicitly connected with OOP.
You also mentioned data hiding, another term that is usually mixed with encapsulation.
All I'm saying is that there are very similar terms that are connected with each other.
Anyway, beautiful video. One of the greatest channels. Thanks for creating this content for free!
Thank you, and you are most welcome. I can see where you're coming from. An API is a way that a programmer can utilise the code someone else has written without being able to see 'under the bonnet'. In that sense, the API code is encapsulated. The most used definition of encapsulation is "the hiding of data and complexity", but it is also a way that an organisation can protect their intellectual property, that is, their source code. Many people confuse encapsulation with abstraction. Abstraction is to "ignore detail". If you are a studying for an exam and might get asked questions about OOP, then the definitions are important.
@@ComputerScienceLessons OOP provides abstraction, all right, but it provides the wrong abstraction for the overwhelming majority of problems because the "functions act mostly on data inside their own class" assumption is usually not even remotely correct. As soon as there are strong dependencies between data elements in different classes (and there almost always are), OOP becomes an unsolvable puzzle.
And just like that, I subscribed to this channel for such a great explanation.
Clear, concise, and informative. Thanks!
Clear and to the point, thank you!
Thank you for your brilliant explaination. I now know why OOP does not work for my type of programming. I deal with mathematical processes and not objects. Data goes in, formulas are applied, results come out, results are stored or presented. OOP fits database problems. My programming fit the chsos of a spreadsheet.
that was bloody fanatic mate cheers for that
You're welcome :)KD
The clarity at its peak. 👌
took me 6 seconds to decide i love this video thanks for this subbed and commenting for the algorithm
Thank you. Subbed U 2 :)KD
@@ComputerScienceLessons me back 1 year later and still loving your content
had so many doubts after my OOP class this cleared it all
Delighted to help. :)KD
Loved the video and how you emphasize different key words, keep the great work!
Thank you. The animations took ages :)KD
so clear, and easy to understand, thanks
great job
You're welcome. And thank you :)KD
Very solid explanation, perfect breakdown. Thank you for sharing.
You are very welcome. Thank you :)KD