Java OCA OCP Practice Question 1029

Question

Which of the following is true about a concrete subclass?

Choose all that apply

  • A. A concrete subclass can be declared as abstract.
  • B. A concrete subclass must implement all inherited abstract methods.
  • C. A concrete subclass must implement all methods defined in an inherited interface.
  • D. A concrete subclass cannot be marked as final.
  • E. Abstract methods cannot be overridden by a concrete subclass. 


B.

Note

Concrete classes are, by definition, not abstract, so option A is incorrect.

A concrete class must implement all inherited abstract methods, so option B is correct.

Option C is incorrect; a superclass may have already implemented an inherited interface, so the concrete subclass would not need to implement the method.

Concrete classes can be both final and not final, so option D is incorrect.

Finally, abstract methods must be overridden by a concrete subclass, so option E is incorrect.




PreviousNext

Related