A. An abstract class can be extended.
B. A subclass of a non-abstract superclass can be abstract.
C. A subclass can override a concrete method in a superclass to declare it abstract.
D. An abstract class can be used as a data type.
E. All of the above
Answer: Option E
This Question Belongs to Java Program >> Interfaces And Abstract Classes
A. A contract specifying a set of methods that a class must implement
B. A class that cannot be instantiated
C. A class that contains only static methods
D. A subclass of the Object class
In Java, can a class implement multiple interfaces?
A. Interfaces cannot be implemented by classes
B. Only abstract classes can implement interfaces
C. No, a class can only implement one interface
D. Yes, a class can implement multiple interfaces
What is the purpose of an abstract class in Java?
A. To declare abstract methods
B. To provide a base class with common methods and fields
C. To make a class final
D. None of These
Option B) A subclass of a non-abstract superclass can be abstract
And
Option D) An abstract class can be used as a datatype
I don't know before those options is true.
I felt option B is not true regarding abstract class