177. Given: 

11. String test = "This is a test"； 

12. String[] tokens = test.split("s")； 

13. System.out.println(tokens.length)； 

What is the result?
(A) 0
(B) 1
(C) 4
(D) Compilation fails.
(E) An exception is thrown at runtime.

172. Given: 33. Date d = new Date(0)； 34. String ds = "December 15, 2004"； 35. //insert code here 36. try{ 37. d = df.parse(ds)； 38. } 39. catch(ParseException e){ 40. System.out.println("Unable to parse " + ds)； 41. } 42. //insert code here too What creates the appropriate DateFormat object and adds a day to the Date object? (A) 35. DateFormat df = DateFormat.getDateFormat()； 42. d.setTime((60 * 60 * 24) + d.getTime()； (B) 35. DateFormat df = DateFormat.getDateInstance()； 42. d.setTime((1000 * 60 * 60 * 24) + d.getTime())； (C) 35. DateFormat df = DateFormat.getDateFormat()； 42. d.setLocalTime((1000 * 60 * 60 * 24) + d.getLocalTime())； (D) 35. DateFormat df = DateFormat.getDateInstance()； 42. d.setLocalTime((60 * 60 * 24) + d.getLocalTime())；

173. Given: 11. public class Yikes{ 12. 13. public static void go(Long n){System.out.print("Long ")；} 14. public static void go(Short n){System. outprint("Short ")；} 15. public static void go(int n){System.out.print("int ")；} 16. public static void main(String[] args){ 17. short y = 6； 18. long z = 7； 19. go(y)； 20. go(z)； 21. } 22. } What is the result? (A) int Long (B) Short Long (C) Compilation fails. (D) An exception is thrown at runtime.

174. Given: 12. Date date = new Date()； 13. df.setLocale(Locale.ITALY)； 14. String s = df.format(date)； The variable df is an object of type DateFormat that has been initialized in line 11. What is the result if this code is run on December 14, 2000? (A) The value of s is 14-dic-2000. (B) The value of s is Dec 14, 2000. (C) An exception is thrown at runtime. (D) Compilation fails because of an error in line 13.

複選題175. Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object? (Choose two.) (A) When using versions of Java technology earlier than 5.0. (B) When sharing a StringBuffer among multiple threads. (C) When using the java.io class StringBufferInputStream. (D) When you plan to reuse the StringBuffer to build more than one string. (E) Enitiation of separate design processes to the separation of users

178. Given: 1. public class Target{ 2. private int i = 0； 3. public int addOne(){ 4. return ++i； 5. } 6. } And: 1. public class Client{ 2. public static void main(String[] args){ 3. System.out.println(new Target().addOne())； 4. } 5. } Which change can you make to Target without affecting Client? (A) Line 4 of class Target can be changed to return i++； (B) Line 2 of class Target can be changed to private int i = 1； (C) Line 3 of class Target can be changed to private int addOne(){ (D) Line 2 of class Target can be changed to private Integer i = 0；

185. Given: 1. public class Person{ 2. private String name；  3. public Person(String name){this.name = name；} 4. public boolean equals(Person p){ 5. return p.name.equals(this.name)； 6. } 7. } Which statement is true? (A) The equals method does NOT properly override the Object.equals method. (B) Compilation fails because the private attribute p.name cannot be accessed in line 5. (C) To work correctly with hash-based data structures, this class must also implement the hashCode method. (D) When adding Person objects to a java.util.Set collection, the equals method in line 4 will prevent duplicates.

複選題186. Which two statements are true about the hashCode method? (Choose two.) (A) The hashCode method for a given class can be used to test for object equality and object inequality for that class. (B) The hashCode method is used by the java.util.SortedSet collection class to order the elements within that set. (C) The hashCode method for a given class can be used to test for object inequality, but NOT object equality, for that class. (D) The only important characteristic of the values returned by a hashCode method is that the distribution of values must follow a Gaussian distribution. (E) The hashCode method is used by the java.util.HashSet collection class to group the elements within that set into hash buckets for swift retrieval.

187. Given: 1. public class Score implements Comparable＜Score＞{ 2. private int wins, losses； 3. public Score(int w, int l){wins = w； losses = l；} 4. public int getWins(){return wins；} 5. public int getLosses(){return losses；} 6. public String toString(){ 7. return "＜" + wins + "," + losses + "＞"； 8. } 9. //insert code here 10. } Which method will complete this class? (A) public int compareTo(Object o){/* more code here */} (B) public int compareTo(Score other){/* more code here */} (C) public int compare(Score s1, Score s2){/* more code here */} (D) public int compare(Object o1, Object o2){/* more code here */}

189. 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. } What is the result? (A) Compilation fails due to an error in line 23. (B) Compilation fails due to an error in line 29. (C) A ClassCastException occurs in line 29. (D) A ClassCastException occurs in line 31. (E) The value of all four objects prints in natural order.

190. Given: 1. import java.util.*； 2. public class WrappedString{ 3. private String s； 4. public WrappedString(String s){this.s = s；} 5. public static void main(String[] args){ 6. HashSet＜Object＞ hs = new HashSet＜Object＞()； 7. WrappedString ws1 = new WrappedString("aardvark")； 8. WrappedString ws2 = new WrappedString("aardvark")； 9. String s1 = new String("aardvark")； 10. String s2 = new String("aardvark")；11. hs.add(ws1)； hs.add(ws2)； hs.add(s1)； hs.add(s2)； 12. System.out.println(hs.size())； }} What is the result? (A) 0 (B) 1 (C) 2 (D) 3 (E) 4