SoCalBruce

 Profile Answers by SoCalBruce 

• Dec 3rd, 2007

 

An abstract class can ONLY be overridden by a virtual method.  If the method is not virtual then the abstract method is "hidden".

 

The "override" also means the member is virtual.  For example, Derived.Method is a virtual method:

 
public abstract class Base
{
    public abstract void Method ( );
}
 
public class Derived : Base
{
    public override void Method ( )
    {
    }
}

whirlpool

 Profile Answers by whirlpool 

• Dec 26th, 2007

 

When an abstract class inherits a virtual method from a base class, the abstract class can override the virtual method with an abstract method.

Answer is True.

mahmood pasha

 Profile Answers by mahmood pasha 

• Jul 1st, 2008

 

It is designed to act as derived class. the class , which contain more virtual function is called an abstract class. and it cannot be create as an object, and it is similar to Interface

PeterVH

• Aug 19th, 2011

 

Hello Raj,

you override methods, not classes. So, guessing you mean abstract methods.
The overriding method can NEVER be virtual, but by using the "new" keyword you can *replace* the abstract method, not override. You can override an abstract method with another abstract method however.

Basically:
The overridden base method must be virtual, abstract, or an "override" itself.
The overriding (derived) method cannot use new / static / virtual.

Code
    public abstract class MeaningOfLife


    {


        // The overridden base method must be virtual, abstract, or override.


        public abstract int GiveMeTheMeaningAbstract();


        public virtual int GiveMeTheMeaningVirtual()


        {


            // I don't know, let's just return a random number


            return DateTime.Now.Millisecond;


        }


    }


 


    // could also make this class abstract, but no need for it


    public class AccordingToHitchHikers : MeaningOfLife


    {


        // needs the override to implement, otherwise won't compile


        public override int GiveMeTheMeaningAbstract() { return 42; }


 


        // you can leave out the override here (will compile), 


        // but then you aren't overriding but hiding. In that case add "new" keyword


        public override int GiveMeTheMeaningVirtual() { return 42; }


    }


 


    // Needs to be abstract, as it has an abstract member


    public abstract class WhatIsLife : MeaningOfLife


    {


        // you can override an abstract method with another abstract one 


        // (for what use I still don't really know..


        public override abstract int GiveMeTheMeaningAbstract();


    }