205. Given: 

12. import java.util.*； 

13. public class Explorer2{ 

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

15. TreeSet＜Integer＞ s = new TreeSet＜Integer＞()； 

16. TreeSet＜Integer＞ subs = new TreeSet＜Integer＞()； 

17. for(int i=606； i＜613； i++) 

18. if(i%2 == 0) s.add(i)； 

19. subs = (TreeSet)s.subSet(608, true, 611, true)；

 20. s.add(629)；

 21. System.out.println(s + " " + subs)；

 22. }

 23. }

 What is the result?
(A) Compilation fails.
(B) An exception is thrown at runtime.
(C) [608, 610, 612, 629] [608, 610]
(D) [608, 610, 612, 629] [608, 610, 629]
(E) [606, 608, 610, 612, 629] [608, 610]

19. 進行試題分析時，選取高分組或低分組的人數比例，下列何者較為合 適? (A)最高分與最低分各選取 5% (B)最高分與最低分各選取 12% (C)最高分與最低分各選取 27% (D)最高分與最低分各選取 49%

20. 王老師自編一份 50 題的測驗，以評量學生的學習成就。經過試題分析 後，下列哪一項做法最可能提高此測驗的信度? (A)刪除難度值為 0 的題目 (B)刪除難度值為 1 的題目 (C)刪除與總分負相關的全部題目 (D)刪除與總 分正相關較低的題目

203. Given: 5. import java.util.*； 6. public class SortOf{ 7. public static void main(String[] args){ 8. ArrayList＜Integer＞ a = new ArrayList＜Integer＞()； 9. a.add(1)； a.add(5)； a.add(3)； 10. Collections.sort(a)； 11. a.add(2)； 12. Collections.reverse(a)； 13. System.out.println(a)； 14. } 15. } What is the result? (A) [1, 2, 3, 5] (B) [2, 1, 3, 5] (C) [2, 5, 3, 1] (D) [5, 3, 2, 1] (E) [1, 3, 5, 2]

204. Given: 11. public class Person{ 12. private name； 13. public Person(String name){ 14. this.name = name； 15. } 16. public int hashCode(){ 17. return 420； 18. } 19. } Which statement is true? (A) The time to find the value from HashMap with a Person key depends on the size of the map. (B) Deleting a Person key from a HashMap will delete all map entries for all keys of type Person. (C) Inserting a second Person object into a HashSet will cause the first Person object to be removed as a duplicate. (D) The time to determine whether a Person object is contained in a HashSet is constant and does NOT depend on the size of the map.

206. Given: 1. public class Drink implements Comparable{2. public String name； 3. public int compareTo(Object o){ 4. return 0； 5. } 6. } and: 20. Drink one = new Drink()； 21. Drink two = new Drink()； 22. one.name = "Coffee"； 23. two.name = "Tea"； 24. TreeSet set = new TreeSet()； 25. set.add(one)； 26. set.add(two)； A programmer iterates over the TreeSet and prints the name of each Drink object. What is the result? (A) Tea (B) Coffee (C) Coffee Tea (D) Compilation fails. (E) The code runs with no output.

207. A programmer must create a generic class MinMax and the type parameter of MinMax must implement Comparable. Which implementation of MinMax will compile? (A) (B) (C) (D)

208. 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()； (C) Set set = new SortedSet()； (D) List set = new SortedList()； (E) Set set = new LinkedHashSet()；

209. Given:  1. import java.util.*； 2. public class TestSet{ 3. enum Example{ONE, TWO, THREE} 4. public static void main(String[] args){ 5. Collection coll = new ArrayList()； 6. coll.add(Example.THREE)； 7. coll.add(Example.THREE)； 8. coll.add(Example.THREE)； 9. coll.add(Example.TWO)； 10. coll.add(Example.TWO)； 11. coll.add(Example.ONE) 12. Set set = new HashSet(coll)； 13. } 14. } Which statement is true about the set variable on line 12? (A) The set variable contains all six elements from the coll collection, and the order is guaranteed to be preserved. (B) The set variable contains only three elements from the coll collection, and the order is guaranteed to be preserved. (C) The set variable contains all six elements from the coll collection, but the order is NOT guaranteed to be preserved. (D) The set variable contains only three elements from the coll collection, but the order is NOT guaranteed to be preserved.

210. Given: 11. public class Person{ 12. private String name, comment； 13. private int age； 14. public Person(String n, int a, String c){ 15. name = n； age = a； comment = c； 16. } 17. public boolean equals(Object o){ 18. if (!(0 instanceof Person)) return false； 19. Person p = (Person)o； 20. return age == p.age && name.equals(p.name)； 21. } 22. } What is the appropriate definition of the hashCode method in class Person? (A) return super.hashCode()； (B) return name.hashcode() + age * 7； (C) return name.hashCode() + comment.hashCode() / 2； (D) return name.hashCode() + comment.hashCode() / 2- age * 3；

複選題211. Given: 11. public class Key{ 12. private long id1, 13. private long id2； 14. 15. //class Key methods 16. } A programmer is developing a class Key, that will be used as a key in a standard java.util.HashMap. Which two methods should be overridden to assure that Key works correctly as a key? (Choose two.) (A) public int hashCode() (B) public void hashCode() (C) public int compareTo(Object o) (D) public boolean equals(Object o) (E)public boolean compareTo(Key k)