Java Polymorphism: Compile time vs. Run time. Method Overloading vs. Overriding #17

[@BoxerDogs]

Instead of doing Animal animal2 = new Dog(); why wouldn't you use: Dog animal2 = new Dog(); since animal2 is of the type Dog?

[@smartherd]

Everything in the video is done for some purpose. Animal animal = new Dog() shows that u can assign the sub class object of Dog to the super class reference of Animal but vice versa is not possible.

[@BoxerDogs]

I understand that you can assign the sub class object of Dog to the super class reference of Animal but vice versa. Here is what I don't understand. You can also do: Dog animal2 = new Dog(); animal2.eat();and still get "Dog Eating" as the result. So if create a dog object as type Animal (superclass) or as type Dog (subclass) either way the end result is still "Dog Eating." So if the result is the same whether a new dog object is of type Animal or type Dog, what is the advantage of defining a new dog object as type Animal? Why might somebody do this?

[@smartherd]

It is the question of runtime. In the runtime if you are not sure what will be your object type then you should go for this approach. For example we often pass ArrayList object to a function which has super interface reference of List. If it still doesn't make things clear then here is a complete basic article on it, www.geeksforgeeks.org/referencing-subclass-objects-subclass-vs-superclass-reference/ . Hope it helps :)

[@nightmarionetteprimordial3580]

I hoped you finished this play list my dude! I guess he must have been planing to explain it or you had an influence on his other videos regardless he did state it takes time to make videos. Nevertheless, it took me along time to get here I hope you didn’t watch these straight through. Hahah I found out it’s good to download code and look at it to study what there doing with it from git hub. And seen this a lot! I knew it was going to be important. He is right, everything was done for a reason!

[@TheDivineChords]

I do have the same question and I am not convinced with the response yet

[@sangeetakumar3857]

Finally !! My main Java concepts are clear after watching your simple and high quality videos/presentation. I feel more confident now to face any upcoming interviews. Thanks a lot !

[@jasonsmith-iw4gm]

I am a seasoned Java programmer. But to teach my high school kid, I came across this video about polymorphism. By far, this is the BEST VIDEO for explanation on POLYMORPHISM. GOD bless you for putting together such a great video.

[@tahajunaid9834]

your videos are so well explained thank you. i especially like how you summarize the videos

[@منامريكا-ر4ه]

You were awesome I made me strong understanding the pleomorphism

[@technophile7024]

Awesome tutorial, very clear to understand, top notch! Thanks for posting such a great video.

[@smartherd]

Thanks

[@sintushukla6709]

Guy's, After filtering many lecture's for Java. I found it the best one. Thankyou @smartherd

[@equinox6833]

I have presentation tomorrow and u made it crystal clear .Very informative video thank you . Btw your voice is really nice

[@Tikorungbaka]

When overloading, you must change either the type or the number of parameters for a method. Method overloading is done to allow us to use the same methods names for multiple methods. The purpose behind this is that, you might have different functionality implementation for the same feature based on the difference in parameters and in that scenario you definitely want the same method names to be able to relate all of them with the feature. Overriding means that a method inherited from a parent class will be changed. But, when overriding a method everything remains exactly the same except the method implementation. What the method does is changed to fit in with the needs of the child class. But, the method name, the number and types of parameters, and the return type will all remain the same.

[@poojapalwai6064]

The contents of your videos is very well organized and explained , thank you for the video...

[@gs-rc3eq]

that is ine good explanation on run time polymorphism and upcasting with super class....thank you!!! this cleared a big confusion for me....

[@rohitr6722]

great video sir, love ur style of explanation

[@himanshusinghnegi3639]

your videos are awesome !!!! i have learned many new concepts through this playlist .... so thanks for providing us such great content !!!

[@smartherd]

I love teaching. U love learning. Deal!

[@guruprasadr7886]

Thanks a lot Sriyank Siddhartha sir, i strengthened my java knowledge and learnt some additional concepts in java through your videos

[@coderbravo1275]

Perfectly explained. Thank you Sir :)

[@emanalikhan591]

bahi tum kitna acha samjhaty hou yaar ...itna khabi mami papa ney nhi samjhaya acha ...bahi love you hou gya bahi

[@felixgerschner]

Insane quality. Thank you for these videos.

[@SmartProgramming]

really great, keep it up, thank you 👍👍👍👍🙂🙂🙂🙂

[@shwetatripathi9093]

Simply Amazing explanation! Thanks a lot.

[@shubhjeetrajput2505]

videos are informative and very clear, you can also tell the theoretical part for interview propectives

[@rahulmandal6139]

Great conceptual explanation 😊😊😊😊😊👨‍💻👨🏻‍💻

[@reynaldosilva1115]

Thank you for sharing your knowledge!

[@Overlanding_America]

this was super helpful thank you

[@mani76969]

Hi Mr.Siddhartha am watching your Java Tutorial all videos and I take notes also, you have Good teaching knowledge please put more more videos for based on programming. Thank you vary much

[@vaibhav0809]

great...very well explained by @Smartherd

[@evergreencreations6232]

Tq sir for your video. I got a clarity about this topic

[@zainwasem]

Top notch very clear.

[@malumalu5594]

thanks bro. I can understand easily by like your way of teaching.tqq

[@jitendragorle]

Very nice and clear explanation, thanks siyank

[@smartherd]

+jitendra Gorle thank you

[@gamingsports7250]

Thank you for your java tutorials This videos clear my all java concept

[@smartherd]

thank you very much 😉

[@shree4046]

Hello sir I have downloaded all.your Java tutorials..plz continue.i wanna learn

[@smartherd]

sure. But just a request do not download. watch it online if possible. This is our living

[@souravkarjole7587]

is below what i stated is correct ? Thank You🙇‍♂🙇‍♂ Compile-time: The compiler checks if the methods you are trying to call exist in the reference type (interface or class) and whether they have the correct signatures. Runtime: The program runs, and when a method is called using an object, it checks the type of the actual object being referred to (which is determined at runtime). Then, it looks for the appropriate method in the actual object's class hierarchy and executes that method.

[@subasubashni9014]

I think it's right! And this is what I was trying to comprehend. Thanks.

[@spenceremmanuel7563]

Thanks for posting such a great video!

[@SurajKumar-mq9ww]

nice explanation brother

[@atulsoni9600]

Great explanation

[@BeeshoStudying]

thank you for the video

[@potturikaruna4152]

nice sir each and every topic vedios we need

[@Masarap1959]

Perfect! BUT could we need to extends keyboard when we used reference variable to other class object?

[@Tikorungbaka]

we use extends keyword to define a child class so that it inherits from a parent class

[@sagarvarma3919]

It really helped 😊

[@dhrock251]

+Smartherd great work....5 videos in one day...

[@shh1909]

Great videos great playlist

[@samudragupta719]

Good explanation Indeed !

[@smartherd]

Thanks

[@tanishadixit_]

Can l use upcasting normally in java programs where l haven't declared method overriding??

[@ManzoorHussain-gz1vk]

thank you very much.

[@luckysuma1769]

Excellent 👍

[@shubhamsutar7567]

nicely explain

[@sachidanandapallai6016]

thank you dear

[@sayanbera28]

is Runtime Polymorphism and Inheritance related? Does Runtime Polymorphism follow Inheritance concept?

[@enamulhaque5697]

nice Lecture bro....Plz upload a lecture about null pointer exception....

[@kanikasarkar7690]

It is too good to understand

[@aravindsagarpa78]

Very nice classes

[@smartherd]

thank you.

[@dhevanrajandran7632]

the best video:)

[@tnkwok9682]

Thank you Sir for your effort in preparing the tutorial. However, I get different result when coding your upcasting example in the IDE. What I got from the following line of codes was "Animal Eating" instead of "Dog Eating": Animal animal2 = new Dog(); animal2.eat(); //result: Animal Eating

[@kamal-coder]

nice sir understand

[@chintadakiranraj7893]

sir how can i get all the videos of java from ur channel and i have subscribed already

[@rahulsoni-lx5rb]

awsm🙌

[@hemanthk2561]

Plzz put video on multi-threading bro...

[@soniafaizabenchebana3128]

merci beaucoup

[@veerraghavareddy735]

Please upload remaining videos by explaining remaining topics like interface,packages,applet and soon in Java because we are the follower of you

[@smartherd]

+Veerraghava Reddy soon I will be up with my website.. Catch you there

[@veerraghavareddy735]

Your site is not opening

[@somareddy3060]

Smartherd

[@vibrantworld4531]

Please upload more videos sir..the advanced videos

[@fazilatali7545]

sir plz make a vedio about the concept of polymorphism using only abstract classes

[@er.abhishek1108]

Well explained. There is one error. In rules of polymorphism, rule no. 3 you have to mention reference variable of child class should not point to parent class object. What you have written is confusing. You have only mentioned reference variable not reference variable of child class.

[@tessythomas9910]

Thanku

[@eunardayangco2987]

I have a class Name Database which has insert(),delete(),update() methods...I have another two class which is InventoryDatabase and UserDatabase. Both of them is inherit the Database..Now InventoryDatabase has its own methods which is getInventory as well as UserDatabase which is loginUser(). Now here is the problems. I call like this: Database db = new InventoryDatabase(); and got no error. But when I call the method like db.getInventory(); and error occurred that getInventory() is not found. I just learn Polymorphism but I don't know exactly why this error was happened. Please help me!

[@indiras8833]

Eventhough you have created an object for InventoryDatabase, your reference variable is of type Database. so you cant invoke subclass methods. Simply if you are having a reference of a super class for the object of a sub class, then you can only call the methods in the superclass with that reference.

[@mathukumallipallavi8795]

Excellent...

[@smartherd]

thank you very much 😉

[@manjusha9630]

How can you then call eat method in animal class and print animal eating in main method You will simply create animal object then what is the use of extending

[@manjusha9630]

You have well explained the reference and object but compile time run time u didn’t explain

[@consejosparasermejor4451]

A question: Is there any way to use method overriding and overloading at the same time?

[@smartherd]

Yes u can do it. Y not

[@khouloudbentaoues641]

@@smartherd oveloading requires to change the parameters or the return type of a method while in overriding the signature and the return type stay the same so how is that possible ?

[@tshepojaphta8718]

thanks is clear

[@smartherd]

Thanks alot. Make sure you visit www.smartherd.com/ . A lot of content will be there soon

[@kumar17299]

it's to listen. But if it is executable code, then that will more make sense.

[@smartherd]

Watch next video for the demo and code mate

[@chetanchavan1187]

thanks

[@FahimAhmed-iq7do]

class name Animal and method name is add. what the work of add method in animal class?

[@manzoorahmad3519]

Please Upload more videos of java

[@smartherd]

+Manzoor Ahmad it's the end bro... U can now go ahead with Java programming

[@sadaffatima2076]

Great

[@BeFox]

Bhai please hindi mein padao kasam se jabardast videos hai aapke

[@varshamehra8164]

nice

[@vibrantworld4531]

Sir please upload more videos

[@mrtayyabmughal7209]

Plz upload next parts

[@sagarsinghrajpoot6788]

Nice ;)

[@manjusha9630]

After upcasting if is giving child class method what is the use of upcasting

[@HumphreyTembo-d4p]

woww

[@theartist8835]

The question here is what is it that you can do with this Animal animal2 = new Dog(); that you can not do with this Dog animal2 = new Dog();

[@barshabhattacharjee6788]

For more : kzbin.info/www/bejne/p2O1mHl-ZteDpdU

[@thilwai.4238]

IT tutorial on utube is not the platform to show off your English communication skills...it would be more better if you had explained this lecture in Hindi...

[@redpersimmon6940]

Thankyou

[@abhinandkk4681]

thankyou