Garbage Collection Ques: 02

Garbage Collection Ques: 02 

Given:

11. public void genNumbers() {

12. ArrayList numbers = new ArrayList();

13. for (int i=0; i<10 font="" i="">

14. int value = i * ((int) Math.random());

15. Integer intObj = new Integer(value);

16. numbers.add(intObj);

17. }

18. System.out.println(numbers);

19. }

Which line of code marks the earliest point that an object referenced by intObj becomes a candidate for

garbage collection?

A. Line 16

B. Line 17

C. Line 18

D. Line 19

E. The object is NOT a candidate for garbage collection.

Answer: D

Garbage Collection Ques: 01

Garbage Collection 

Ques: 01 Given:

1. public class GC {

2. private Object o;

3. private void doSomethingElse(Object obj) { o = obj; }

4. public void doSomething() {

5. Object o = new Object();

6. doSomethingElse(o);

7. o = new Object();

8. doSomethingElse(null);

9. o = null;

10. }

11.}

When the doSomething method is called, after which line does the Object created in line 5 become

available for garbage collection?

A. Line 5

B. Line 6

C. Line 7

D. Line 8

E. Line 9

F. Line 10

Answer: D

Exception Handling Ques: 03

Exception Handling

Ques: 03 Given:

31. //some code here

32. try {

33. //some code here

34. } catch (SomeException se) {

35. //some code here

36. } finally {

37. // some code here

38. }

Under which three circumstances will the code on line 37 be executed? (Choose three.)

A. The instance gets garbage collected.

B. The code on line 33 throws an exception.

C. The code on line 35 throws an exception.

D. The code on line 31 throws an exception.

E. The code on line 33 executes successfully.

Answer: B, C, E

Exception Handling Ques: 02

Exception Handling

Ques: 02 Given:

84. try {

85. ResourceConnection con = resourceFactory.getConnection();

86. Results r = con.query("GET INFO FROM CUSTOMER");

87. info = r.getData();

88. con.close();

89. } catch (ResourceException re) {

90. errorLog.write(re.getMessage());

91. }

92. return info;

Which statement is true if a ResourceException is thrown on line 86?

A. Line 92 will not execute.

B. The connection will not be retrieved in line 85.

C. The resource connection will not be closed on line 88.

D. The enclosing method will throw an exception to its caller.

Answer: C

Exception Handling Ques: 01

Exception Handling

Q: 01 Given:

11. public static void parse(String str) {

12. try {

13. float f = Float.parseFloat(str);

14. } catch (NumberFormatException nfe) {

15. f = 0;

16. } finally {

17. System.out.println(f);

18. }

19. }

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

21. parse("invalid");

22. }

What is the result?

A. 0.0

B. Compilation fails.

C. A ParseException is thrown by the parse method at runtime.

D. A NumberFormatException is thrown by the parse method at runtime.

Answer: B

OOPs Ques: 41

Ques: 41 

Given:

10. class One {

11. void foo() { }

12. }

13. class Two extends One {

14. //insert method here

15. }

Which three methods, inserted individually at line 14, will correctly complete class Two? (Choose three.)

A. int foo() { /* more code here */ }

B. void foo() { /* more code here */ }

C. public void foo() { /* more code here */ }

D. private void foo() { /* more code here */ }

E. protected void foo() { /* more code here */ }

Answer: B, C, E

OOPs Ques: 40

Ques: 40 Given:

11. public class ItemTest {

12. private final int id;

13. public ItemTest(int id) { this.id = id; }

14. public void updateId(int newId) { id = newId; }

15.

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

17. ItemTest fa = new ItemTest(42);

18. fa.updateId(69);

19. System.out.println(fa.id);

20. }

21. }

What is the result?

A. Compilation fails.

B. An exception is thrown at runtime.

C. The attribute id in the Item object remains unchanged.

D. The attribute id in the Item object is modified to the new value.

E. A new Item object is created with the preferred value in the id attribute.

Answer: A

OOPs Ques: 39

Ques: 39 Given:

1. interface TestA { String toString(); }

2. public class Test {

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

4. System.out.println(new TestA() {

5. public String toString() { return "test"; }

6. });

7. }

8. }

What is the result?

A. test

B. null

C. An exception is thrown at runtime.

D. Compilation fails because of an error in line 1.

E. Compilation fails because of an error in line 4.

F. Compilation fails because of an error in line 5.

Answer: A