Java OCA OCP Practice Question 2619

Question

What is the result of the following code? 

1: public interface Printable { 
2:    public abstract void print(); 
3: } /*from w  w  w  .j a va2 s .  c om*/
4: public interface Log extends Printable {} 
5: public abstract class ConsoleLog implements Log { 
6:    public abstract void log(); 
7: } 
8: public class DosConsoleLog extends ConsoleLog { 
9:    public void log() { System.out.println("Dos ConsoleLog is logging"); } 
10: }
  • A. It compiles and runs without issue.
  • B. The code will not compile because of line 2.
  • C. The code will not compile because of line 4.
  • D. The code will not compile because of line 5.
  • E. The code will not compile because of line 8.
  • F. It compiles but throws an exception at runtime.


E.

Note

The code does not compile because DosConsoleLog inherits the abstract method print() but does not implement it, therefore the correct answer is E.

B, C, and D are incorrect as they compile for various reasons.

Line 2 compiles, as non-static and non-default interface methods are assumed to have the abstract modifier.

Line 4 compiles without issue as an interface can extend another interface.

Line 5 compiles without issue as an abstract class can implement an interface without implementing any of the abstract methods.

F is incorrect, as Line 8 does not compile.




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