wat is virtual keyword?

If a method, property, indexer or event is declared to be virtual, then it means that it can be overridden in a derived class which wants to provide a specialized implementation.

The signature, return type and access modifier of a virtual method and methods which override it must be the same.

When a virtual member is accessed through a variable of the base class type, the actual type of the object determines which version of the method to call.

For example:

using System;

class Base

{

public virtual void MyMethod()

{

Console.WriteLine("Hello from Base class");

}

class Derived : Base

{

public override void MyMethod()

{

Console.WriteLine("Hello from Derived class");

}

class Test

{

static void Main()

{

Base b = new Base(); // b refers to a Base object

b.MyMethod(); // calls Base.MyMethod

b = new Derived(); // b refers to a Derived object

b.MyMethod(); // calls Derived.MyMethod

Console.ReadKey();

}

2 Replies

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Vulpes13y ago
If a method, property, indexer or event is declared to be virtual, then it means that it can be overridden in a derived class which wants to provide a specialized implementation.

The signature, return type and access modifier of a virtual method and methods which override it must be the same.

When a virtual member is accessed through a variable of the base class type, the actual type of the object determines which version of the method to call.

For example:

using System;

class Base
{
public virtual void MyMethod()
{
Console.WriteLine("Hello from Base class");
}
}

class Derived : Base
{
public override void MyMethod()
{
Console.WriteLine("Hello from Derived class");
}
}

class Test
{
static void Main()
{
Base b = new Base(); // b refers to a Base object
b.MyMethod(); // calls Base.MyMethod
b = new Derived(); // b refers to a Derived object
b.MyMethod(); // calls Derived.MyMethod
Console.ReadKey();
}
}
Rewant Choudhary13y ago
The virtual modifier tells the compiler that when any class derived from class A is used, an override method should be called.

refer this in easy way and understandable

http://www.dotnetperls.com/virtual
http://www.programcall.com/26/csnet/virtual-methods-in-csnet-with-example.aspx