Question

Which among the following best describes abstract classes?

(a) If a class has more than one virtual function, it’s abstract class

(b) If a class have only one pure virtual function, it’s abstract class

(c) If a class has at least one pure virtual function, it’s abstract class

(d) If a class has all the pure virtual functions only, then it’s abstract class

I had been asked this question during a job interview.

I'm obligated to ask this question of Abstract Class topic in division Classes of Object Oriented Programming

Answer 1

Correct answer is (c) If a class has at least one pure virtual function, it’s abstract class

To explain: The condition for a class to be called abstract class is that it must have at least one pure virtual function. The keyword abstract must be used while defining abstract class in java.