what is concrete class and abstract class give their difference?

what is concrete class and abstract class give their difference?


Concrete class is nothing but normal class, we can use as a base class or may not.Not compulsory, it can't contain abstract methods.we can create object and work with this class.

class Sample
{
public void MyMethod()
{..............}
}


Abstract class:- Abstract class is class which declared with a keyword Abstract,
Must be used as a base class.
Only intension to declare a abstract class is to use as a base class,that is we can't create object of this class like concrete class.
It can contain abstract methods as well as concrete(normal) methods.

public abstract class MyClass
{
public void MyMethod()
{..............}

public abstract TestMethod()
{
.........
}
}

Hi Prakashraj,

Abstract class is a class that has no direct instances, but whose descendants may have direct instances.

There are case i which it is useful to define classes for which the programmer never intends to instantiate any objects; because such classes normally are used as bae-classes in inheritance hierarchies, we call such classes abstract classes

These classes cannot be used to instantiate objects; because abstract classes are incomplete. Derived classes called concrete classes must define the missing pieces.

Eg:

public abstract class Geek
{
//...Class implementation

public abstract member()
{

}
}


Concrete class is a normal class, Like,

public class Geek
{

public void method()
{
.....
}
}


Thanks & Regards,
Riju.

If a Class can be used to create object : then it will be Concrete Class
If a Class is not made for Object Creation : then it will be Abstract Class, but it must have a abstract method declaration inside it & without definition. ( If in a class there is a single Abstract function then, this class must be Abstract class)

any thing more