Dynamic Binding (Polymorphism) With The Virtual Keyword

Dynamic Binding (Polymorphism) With The Virtual Keyword | C++ Tutorial

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2 жыл бұрын

How to implement dynamic binding (i.e. dynamic polymorphism) with virtual member functions in C++. Source code: github.com/portfoliocourses/c.... Check out www.portfoliocourses.com to build a portfolio that will impress employers!

Пікірлер: 17

@dwivedys Ай бұрын

This is the best video on static and dynamic polymorphism I have seen among here on YT

@FluxSentor Жыл бұрын

This was such a boon to find. I've been lurking for a while since starting school for computer science. You've really been a help, thanks for explaining so many topics!

@PortfolioCourses Жыл бұрын

You're welcome, I'm really glad to hear the videos have been helpful! :-)

@MohitRaj-1712 2 жыл бұрын

Your videos on OOP topics help me a lot.

@PortfolioCourses 2 жыл бұрын

I'm very glad to hear that they help you Mohit, thank you for sharing that! :-D

@CrabRango 3 ай бұрын

Would you only need to apply the virtual keyword to the base class member function? Or are there cases in which you would need to apply it to derived class member functions?

@ValliNayagamChokkalingam Жыл бұрын

Thanks! I thought that polymorphism just meant that the derived class could be used to access member functions and variables of the parent class. So, in our array with student object pointers, when we create space for medical student object instances, is space for all the member variables of medical student allocated or just the name variable? Thanks! Also, if a function returns a reference to something like "&int add()", just returning an int in the actual function's code is enough right? The compiler will convert the returned int to an int reference, right?

@PortfolioCourses Жыл бұрын

Space for all the member variables will be allocated. If you try returning a constant int like '5' from a function "int& add()" then it should produce an error.

@akashislam9127 Жыл бұрын

if I have a chain of drive class like a semi-diamond and the very bottom class has the base class 3 times do I have to use virtual in all the drived class?

@PortfolioCourses Жыл бұрын

My understanding is that in the derived classes, the member functions will be virtual whether we use virtual or not because they are virtual in the base class: stackoverflow.com/questions/58042421/c-multi-level-inheritance-with-virtual-functions.

@akashislam9127 Жыл бұрын

@@PortfolioCourses I was not taking about that , I meant ambiguity problem. #include using namespace std; template class sim_calculator { public: T x, y; void get() { cout > x >> y; } void calculate() { cout

@akashislam9127 Жыл бұрын

why polymorphism does not work if I make the array on the stack instead of on the heap?

@PortfolioCourses Жыл бұрын

That's a really good question Akash but the answer may be a bit long for a commnet. Some of these answers here explain why polymorphism works with pointers/references: stackoverflow.com/questions/15188894/why-doesnt-polymorphism-work-without-pointers-references. :-)

@akashislam9127 Жыл бұрын

@@PortfolioCourses I'm still not fully clear, I would be grateful if you made a video to clarify this topic

@PortfolioCourses Жыл бұрын

@@akashislam9127 Maybe one day I can do that! 🙂

@germankoga8640 Жыл бұрын

So basically what the virtual keyword does is override the default behavior of a base class function so when polymorphism is in place child clases use their own versions?

@PortfolioCourses Жыл бұрын

Yes, that's basically the idea. The virtual keyword allows derived classes to override the behaviour of the virtual base class method to achieve dynamic aka "runtime" polymorphism. :-)