Inheritance in C#

Question

Hi Everyone, Please let me know the solution of below question : Q.1) Need of Overriding? Thanks and Regards

Shivanand Arur · Answer

Hello Rushal, Overriding is a feature where a Child Class can inherit its parent class and can use the methods of the Parent Class. What is the use of Overriding??? Basically Overriding helps you to write less code by inheriting a parent class and " Reuse " the methods defined in the Parent class. For overriding a method, you first have to define the method in the Parent class with a " Virtual " keyword. Now let me give you a simple example!!! public class ParentClass() { public virtual void Walk() { Console.WriteLine("The Object is walking"); } public virtual void Run() { Console.WriteLine("The Object is running"); } } Now a Human being can walk and run, let it be a male or a female. Even Animals walk and run. But the functioanlity of doing those things is different (2 legged Object(Man/Woman) and 4 legged Object(Animal)) public class Animal : ParentClass { public override void Run() { Console.WriteLine("An Animal runs using its 4 legs"); } } So as you can see, the functionality changed but by using the Virtual and override keyword the Child Class can make use of the Parent Class's functions... Hope this helps you out. Please mark the answer as accpeted, if it helped!!! Thank you!!!

Rushal Arora · Answer

My Title is C# and u have answered in VB.net, shall this make sense?

Shivanand Arur · Answer

Hey Rushal, can U please mark any of the answer as accepted if it helped U. Thanks...

darma teja · Answer

Thanks vulpes

Vulpes · Answer

Darma, If you remove the virtual and override keywords, then the Animal class's Run method is 'hiding' the ParentClass's Run method, rather than overriding it. The difference is that, if an Animal object is assigned to a ParentClass variable and the virtual Run() method is called, then it will be Animal's version that is called, not ParentClass's. In other words, it's the actual type of an object, rather than the type of the variable, which is relevant when overriding a virtual method. In contrast, if Run() were non-virtual but the scenario were otherwise the same, then it would ParentClass's version that was called because that is the type of the variable This example illustrates the difference: using System; public class ParentClass { public virtual void Walk() // virtual { Console.WriteLine("The Object is walking"); } public void Run() // non-virtual { Console.WriteLine("The Object is running"); } } public class Animal : ParentClass { public override void Walk() //overriding { Console.WriteLine("An Animal walks using its 4 legs"); } public new void Run() // hiding - 'new' used to suppress compiler warning { Console.WriteLine("An Animal runs using its 4 legs"); } } class Test { static void Main() { ParentClass a = new Animal(); a.Walk(); a.Run(); Console.ReadKey(); } } The output is: An Animal walks using its 4 legs The Object is running

darma teja · Answer

Hi Shivanand, I did your example without keyword "virtual" and "override" and it works. Is it ok if i dont use "virtual" and "override" keywords in overriding. Darma

Santhosh Kumar Jayaraman · Answer

Take this example.. There is a parent class called shape. it has some methods such as calculatearea and calculateVolume. And it has some method implementation. Now when you have child class circle, it will also has same method, but the implementation i.e formula/calculation will be different. Similarly for sphere, square. So there will be a common method calcualte area for most of the shapes, but for some of the child classes can have their own area calculation logic. So we need to go for overriding.

Satyapriya Nayak · Answer

In VB.net Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Overriding : - It is the characteristics of the child or derived class, which overrides the characteristics of the parent class. The procedure in the base class, which could be overrides, is prefixed with the keyword Overridable . The procedure in the child class, which Overrides the base class procedure, is prefixed with the keyword overrides. Mybase keyword is used in the child class to call the parent class procedure. Program Public Class Form2 Dim a As New sagar1 Dim b As New sagar2 Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click MsgBox(a.amit(10, 20)) MsgBox(b.amit(10, 20)) End Sub Public Class sagar1 Public Overridable Function amit( ByVal x As Integer , ByVal y As Integer ) Dim z As Integer z = x + y Return z End Function End Class Public Class sagar2 Inherits sagar1 Public Overrides Function amit( ByVal x As Integer , ByVal y As Integer ) Dim z As Integer z = MyBase .amit(x, y) * 5 Return z End Function End Class End Class Thanks /* Style Definitions */ table.MsoNormalTable{mso-style-name:"Table Normal";mso-tstyle-rowband-size:0;mso-tstyle-colband-size:0;mso-style-noshow:yes;mso-style-priority:99;mso-style-qformat:yes;mso-style-parent:"";mso-padding-alt:0in 5.4pt 0in 5.4pt;mso-para-margin:0in;mso-para-margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:11.0pt;font-family:"Calibri","sans-serif";mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:"Times New Roman";mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}