C++ Programming - OOPS Concepts - Discussion

So why we use abstract class can anyone explain?

Can anyone provide simple programmer illustrating concept of abstract class?

No object is created of abstract class it has no instance.

Can anyone write an executable program for abstract class?

Is instance or object is same?

Abstract Class: A class is called as abstract class if it must have one or more abstract method.

Abstract method: Method which we just declare but not define, every class which inherits abstract class containing abstract method must define that method in its own way.

Abstract class can't have an instance object or variable because if we create an object of abstract class and using that object if we try to access abstract method then we will get compile time error as we don't have anything inside abstract method of that abstract class.

So let's say we have a team creating a big project and we want the whole team to create many classes but they all must inherit a single BASE class for some particular functionality like debugging. So if we would create an abstract class which has only one virtual function which gives a debugging interface and inherits this is in all the other team's classes it would be easier. Why virtual because the derived classes could also have the same function with the same signature.

Which class has maximum instances, Can anyone tell the types of class having instances?

We can not create the instance of the Abstract Class.

So answer will be zero (o) instance of the abstract class.

The abstract class contains at least one pure virtual function.

The pure virtual function by using a pure specifier ( = 0 ).