VB.NET 2013: Classes - Inheritance and Polymorphism

[@qaisarqadeer3370]

very easy and simple way to teach someone about Classes. By far the best method of teaching!

[@b3zzi]

Legend! Explaining concepts that expensive textbooks can't

[@GaryHutsonVBA]

I have bought 4 VB.Net books and basically I am going to chuck them out, because that description of how to use inheritance is the best I have seen. Your sir, are a legend!

[@jeremy75414321]

Great Explanation of classes, I've been studying programming for about 1 year with different techniques and tutorials. This is by far the easiest to understand VB.net tutorial playlist. Thanks for the tutorials, I am learning to think like a programmer now.

[@michaelfaust5191]

Thank you so much for the explanation you've given in this video! You can't imagine how much your videos have taught me about classes and their properties!

[@TailSpin46]

For a good example of inheritance an polymorphism, look for an implementation of the shape example. Most good examples will explain it well. Keep up the good videos Nicholas.

[@hondatuner83]

Simple but good explanation. Well done. It's good to brush up on these. I forget some of these very basic things that I should be trying to implement in my daily coding.

[@sa1998ba]

Man!! you're a truly legend!

[@ga7853]

That was great Nicolas, you have made polymorphism simple remember. Thanks

[@mef9327]

9:51 since volume is area times depth, can you call the cRectangle GetArea() and multiply it by depth? For example, “MyBase.GetArea() * _depth_” Is that possible or is their another way so that changes to the base class formula automatically propagate through the inheriting class?

[@mermaidoasis8452]

Very beautiful video Nicholas. Your name looks Greek. I am from Greece too. However, I have some questions please. It would be my pleasure to answer me. First question at the Cube class, inside the sub New with the three arguments width, height and depth. You wrote MyBase.New(Width,Height) and depth=_depth. Couldn't we say directly MyBase.New(Width,Height,Depth) ? And secod question please, is about polymorphism. What is the difference between two same functions GetArea of both classes at the body of them? Do we have only to the original class GetArea function return _width * _height and does really the system recognise these both similar functions with the overloads keyword? And let's extent a little bit that question what would happen if at the cube class we added parameters to the overloaded function GetArea? For example Overloads Function GetArea (byRef _width, byRef _height, byRef _depth) would we have any error about arguments even passing byRef or byVal respectively? Thank you so much in advanced.

[@tshehlatefokhulwane5318]

..A good video indeed. Thank you Sir.

[@michaelnewman9645]

A simple but good tutorial. However, I need something more advanced. I want to modify a datagridview combobox to have a button with text above the dropdown list. The button will be used for adding items to the data table bound to the combobox. When the button is clicked, a new form is opened where the new data table item an be entered.I have looked at the only example that I can find on the web which is for creating a date column but I have not been able to adapt that to meet my needs. Can you suggest a good KZbin tutorial that may help me to understand how comboboxes can be adapted in this way?

[@NicholasDingle]

+Michael Newman I honestly haven't done much with datagridviews. I did find this tut www.wpftutorial.net/datagrid.html

[@michaelnewman9645]

Thanks Nicholas but that deals with a datagridview using standard columns. As I have been programming for over ten years, I am familiar with the workings of a DGV. If I could find out how to modify a standard combobox to meet my needs, I think I could modify that to work in a datagridview

[@NicholasDingle]

+Michael Newman That's what I was hoping, but I couldn't really find much on datagridviews like you said.

[@katana7068]

Really good tutorial! Subscribed! Any reason why the Sub isn't public in the cube or did you just forget?

[@NicholasDingle]

If it's Sub New you are referring to it's because you don't really need to specify Private or Public - by default they are Public (and Sub New needs to be public). As for GetArea, I just forgot to put it on. It should be Public.

[@katana7068]

tyvm!

[@aaronarnold3107]

Does coercion only work on subs? I don't see why VB can't select the function with _depth included, and we have to manually tell it to use cCubes version of getarea with the "Overloads" designation.

[@NicholasDingle]

So there is a big difference between Coercion and Overloading. Coercion is purely Subs and Functions which you want to use multiple times but with different number of parameters or different parameter data types. Overloading is only ever for functions which are marked as Overloadable. On such example is the ToString function. ToString already has code and doesn't accept and parameters (by default) and it's marked as Overloadable. This means that you can Overwrite the original function of ToString to whatever function you wish. Tell me if any of this makes sense.

[@aaronarnold3107]

Nicholas Dingle The confusion starts at the 10 minute mark in the video. You state that VB is having trouble because it has a "getarea" function in the cRectangle class, and has a "getarea" function in the cCube class and it doesn't know which one to pick. I figured VB would use coercion to choose the cCube class version of "getarea" because it has the appropriate number of values (height, width, depth) in the parameters . However, it doesn't and you have to use overloading to instruct VB to execute the cCube version of the function.

[@NicholasDingle]

The big difference here, that I can see, is that because they are classes and not just functions in the same module. I'll revisit this when I get the chance and get back to you.

[@ausamabutt9747]

y did u created sub new in class cCube??? And y did u use "new" instead of create (in constructors part) in base class

[@emilie1977]

thank you very much

[@AliEkerci-p9b]

Thomas Paul Rodriguez Jennifer Wilson David

[@justhereforkpop]

??

[@assg914]

I have a cie tomorrow and I love you, Hence I would also suggest that you Accept Islam so that I can pray you go to paradise