How do we declare an abstract class?

Question:How do we declare an abstract class?

1.By providing at least one pure virtual method (function signature followed by ==0;) in a class

2.By declaring at least one method abstract using the keyword ‘abstract’ in a class

3.By declaring the class abstract with the keyword ‘abstract’

4.It is not possible to create abstract classes in C++

R4R Team
R4Rin Top Tutorials are Core Java,Hibernate ,Spring,Sturts.The content on website is done by expert team not only with the help of books but along with the strong professional knowledge in all context like coding,designing, marketing,etc!