Pure Virtual Functions in C++ | C++ Programming tutorials for Beginners

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--------------------------------------------------------------------------------------------- In this video tutorial we will study and understand the concept of pure virtual functions in c++ and also see an example of prure virtual functions in terms of practical code.

Pure Virtual Functions in c++
Sometimes implementation of all function cannot be provided in a base class because we don’t know the implementation. Such a class is called abstract class.
A pure virtual function (or abstract function) in C++ is a virtual function for which we don’t have implementation, we only declare it. A pure virtual function is declared by assigning 0 in declaration. 
Some important facts –
A class is abstract if it has at least one pure virtual function.
We can have pointers and references of abstract class type.
If we do not override the pure virtual function in derived class, then derived class also becomes abstract class.
Abstract classes cannot be instantiated.

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[SimpleSnippets]

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[usmclongrangebrainsurgeon]

The BEST C++ tutorials on Youtube. Excellent thank you

[rengokuhasira]

If you have less time and exams are near i really recommend your channel for quick knowledge awesome man you know how to make people job easy

[sharmass]

wow man really great i watched all ur videos u saved me for tommorows exam great

[mohamedsufian]

I know how to use virtual function, pure virtual function but I can't understand where to use it because instead of using them we can directly use normal member function override then why we use them ?

[GowthamVarmaSrinivasan]

Please clarify:
From the basics we know that we cannot have a pointer or reference without an object bound to it. ( Strictly speaking we can have a nullptr, we are talking about class objects here)
Now, we cannot have objects of abstract class type, and that is true by theory.
So how can we have pointers and references of abstract class type? (2nd fact you mention at 1:40).
Thanks

[hasannaqvi]

Sir, you mean we don't have to calculate the area by calling through a base pointer? Kindly update me

[GbbxK]

Thanks this video and the video on virtual functions helped a lot!

[Sabari-gdfw]

Thanks for explanation...could you please tell me..why we couldn't able to create an object for an abstract class?

[ដង្កូវសៀវភៅ]

You definitely save my life. Thanks for clear explanation.

[awaisrana]

Your tutorials very helpful for me
Thank you sir❤

[SonSon-rqdj]

I did the exact code in my IDE, however, I removed the pure virtual function and it still works fine when creating and calling getArea() methods for the circle and rectangle class. May I know what is a pure virtual function used for?

[fleek]

I still have the same question as before!! Why to use virtual function, when I can run my code even without using virtual function??

[Aman-gwro]

Thank you so much bro .... really helpful !!!

[aman]

Sir thank you for this video...but sir how to be so frequent in speaking English just like you

[tapasvig]

Can u give the program for pure virtual function in c++ .Give the program shorter

[zhalokrahman]

in pure virtual func cant we just give input in the first brac likes getarea(int a)???

[shreedhoni]

In derived class you used public again this is the first you using public in derived class
In previous videos you used public access specifier only in base classes not it derived classes

When I didn't use public access specifier in derived class it showed me an error and it is private
Can you explain why??

[dinesh.p]

Tanmay bro, , Can u make the reactjs tutorials...for us..

[dattabhabal]

what is the use of pure virtual function, I mean if we do not have to implement the function then why should we write that function in our class