Exception handling2

Which of the following are checked exceptions?

class One extends RuntimeException{}

class Two extends Exception{}

class Three extends Error{}

class Four extends One{}

• oneone

• two

• Three

• Four

01 Given:

34. HashMap props = new HashMap();

35. props.put("key45", "some value");

36. props.put("key12", "some other value");

37. props.put("key39", "yet another value");

38. Set s = props.keySet();

39. // insert code here

• Arrays.sort(s);

• s = new TreeSet(s);

• Collections.sort(s);

• s = new SortedSet(s);

Given:

23. Object [] myObjects = {

24. new Integer(12),

25. new String("foo"),

26. new Integer(5),

27. new Boolean(true)

28. };

29. Arrays.sort(myObjects);

30. for(int i=0; i<myObjects.length; i++) {

31. System.out.print(myObjects[i].toString());

32. System.out.print(" ");

33. }

• Compilation fails due to an error in line 23.

• Compilation fails due to an error in line 29.

• A ClassCastException occurs in line 29.

• The value of all four objects prints in natural order.

Given:

1. import java.util.*;

2. public class Example {

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

4. // insert code here

5. set.add(new Integer(2));

6. set.add(new Integer(1));

7. System.out.println(set);

8. }

9. }

Which code, inserted at line 4, guarantees that this program will output [1, 2]?

• A. Set set = new TreeSet();

• B. Set set = new HashSet();

• List set = new SortedList();

• Set set = new LinkedHashSet();

Q: 09 Given:

11. public static Collection get() {

12. Collection sorted = new LinkedList();

13. sorted.add("B"); sorted.add("C"); sorted.add("A");

14. return sorted;

15. }

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

17. for (Object obj: get()) {

18. System.out.print(obj + ", ");

19. }

20. }

What is the result?

• A, B, C,

• B, C, A,

• Compilation fails.

• An exception is thrown at runtime.