Can we write abstract keyword in C++ class?
No, you can't use abstract as a keyword because there is no such keyword available in C++.
If you want make a class as an in C++ abstract you can declare at least one function as pure virtual function.
But in derived class you must provide definition else its give compilation error .
Example:
class A
{
public:
virtual void sum () = 0;
};
note:
You can used abstract as a variable name, class name because, as I told you, abstract is not a keyword in C++.