Java OCA OCP Practice Question 1008

Question

Which statement(s) are correct about the following code? (Choose all that apply) 

public class Rectangle { 
  protected static Integer chew() throws Exception { 
    System.out.println("Rectangle is printing"); 
    return 1; /*from w  ww  . java 2  s.co  m*/
  } 
} 
public class Square extends Rectangle { 
  public Number chew() throws RuntimeException { 
    System.out.println("Square is printing on wood"); 
    return 2; 
  } 
}
  • A. It will compile without issue.
  • B. It fails to compile because the type of the exception the method throws is a subclass of the type of exception the parent method throws.
  • C. It fails to compile because the return types are not covariant.
  • D. It fails to compile because the method is protected in the parent class and public in the subclass.
  • E. It fails to compile because of a static modifier mismatch between the two methods. 


C, E.

Note

The code doesn't compile, so option A is incorrect.

Option B is also not correct because the rules for overriding a method allow a subclass to define a method with an exception that is a subclass of the exception in the parent method.

Option C is correct because the return types are not covariant; in particular, Number is not a subclass of Integer.

Option D is incorrect because the subclass defines a method that is more accessible than the method in the parent class, which is allowed.

Finally, option E is correct because the method is declared as static in the parent class and not so in the child class.

For non-private methods in the parent class, both methods must use static (hide) or neither should use static (override).




PreviousNext

Related