JAVA DUMPS 18 (SCJP)

QUESTION NO: 1

Given:

1. public class Test {

2. public static void main(String args[]) {

3. class Foo {

4. public int i = 3;

5. }

6. Object o = (Object)new Foo();

7. Foo foo = (Foo)o;

8. System.out.println("i = " + foo.i);

9. }

10. }

What is the result?

A. i = 3

B. Compilation fails.

C. A ClassCastException is thrown at line 6.

D. A ClassCastException is thrown at line 7.

Answer: A

 

QUESTION NO: 2

Which two cause a compiler error? (Choose two)

A. float[] = new float(3);

B. float f2[] = new float[];

C. float[] f1 = new float[3];

D. float f3[] = new float[3];

E. float f5[] = { 1.0f, 2.0f, 2.0f };

F. float f4[] = new float[] { 1.0f. 2.0f. 3.0f};

Answer: A, B

QUESTION NO: 3

Given:

11. int i =1,j =10;

12. do {

13. if(i++> --j) {

14. continue;

15. }

16. } while (i <5);

17. System.out.println("i = " +i+ "and j = "+j);

What is the result?

A. i = 6 and j = 5

B. i = 5 and j = 5

C. i = 6 and j = 5

D. i = 5 and j = 6

E. i = 6 and j = 6

Answer: D

 

QUESTION NO: 4

Given:

1. class Test {

2. private Demo d;

3. void start() {

4. d = new Demo();

5. this.takeDemo(d);

6. }

7.

8. void takeDemo(Demo demo) {

9. demo = null;

10. demo = new Demo();

11. }

12. }

When is the Demo object, created on line 3, eligible for garbage collection?

A. After line 5.

B. After line 9.

C. After the start() method completes.

D. When the takeDemo() method completes.

E. When the instance running this code is made eligible for garbage collection.

Answer: E

QUESTION NO: 5

Given:

1. interface Animal {

2. void soundOff();

3. }

4.

5. class Elephant implements Animal {

6. public void soundOff() {

7. System.out.println("Trumpet");

8. }

9. }

10.

11. class Lion implements Animal {

12. public void soundOff() {

13. System.out.println("Roar");

14. }

15. }

16.

17. class Alpha1 {

18. static Animal get( String choice ) {

19. if ( choice.equalsIgnoreCase( "meat eater" )) {

20. return new Lion();

21. } else {

22. return new Elephant();

23. }

24. }

25. }

Which compiles?

A. new Animal().soundOff();

B. Elephant e = new Alpha1();

C. Lion 1 = Alpha.get("meat eater");

D. new Alpha1().get("veggie").soundOff();

Answer: D