第22題 Given: 1. class Pass{ 2. public static void main(String[] args){ 3. int x = 5; 4. Pass p = new Pass(); 5. p.doStuff(x); 6. System.out.print(" main x = " + x); 7. } 8. void doStuff(int x){ 9. System.out.println(" doStuff x = " + x++); 10. } 11. } What is the result?
(A) Compilation fails.
(B) An exception is thrown at runtime.
(C) doStuff x = 6 main x = 6
(D) doStuff x = 5 main x = 5
(E) doStuff x = 5 main x = 6 F. doStuff x = 6 main x = 5

複選題第18題 Given: 1. class Super{ 2. private int a; 3. protected Super(int a){this.a = a;} 4. } ... 11. class Sub extends Super{ 12. public Sub(int a){super(a);} 13. public Sub(){this.a = 5;} 14. } Which two, independently, will allow Sub to compile? (Choose two.) (A) Change line 2 to: public int a; (B) Change line 2 to: protected int a; (C) Change line 13 to: public Sub(){this(5);} (D) Change line 13 to: public Sub(){super(5);} (E) Change line 13 to: public Sub(){super(a);}

第19題 Which Man class properly represents the relationship "Man has a best friend who is a Dog"? (A) class Man extends Dog{} (B) class Man implements Dog{} (C) class Man{private BestFriend dog;} (D) class Man{private Dog bestFriend;} (E) class Man{private Dog;} F. class Man{private BestFriend;}

複選題第20題 A team of programmers is reviewing a proposed API for a new utility class. After some discussion, they realize that they can reduce the number of methods in the API without losing any functionality. If they implement the new design, which two OO principles will they be promoting? (A) Looser coupling (B) Tighter coupling (C) Lower cohesion (D) Higher cohesion (E) Weaker encapsulation F. Stronger encapsulation

第21題 Given: 1. class Batman{ 2. int squares = 81; 3. public static void main(String[] args){ 4. new Batman().go(); 5. } 6. void go(){ 7. incr(++squares); 8. System.out.println(squares); 9. } 10. void incr(int squares){squares += 10;} 11. } What is the result? SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 11 (A) 81 (B) 82 (C) 91 (D) 92 (E) Compilation fails. F. An exception is thrown at runtime.

複選題第23題 A company has a business application that provides its users with many different reports: receivables reports, payables reports, revenue projects, and so on. The company has just purchased some new, state-of-the-art, wireless printers, and a programmer has been assigned the task of enhancing all of the reports to use not only the company's old printers, but the new wireless printers as well. When the programmer starts looking into the application, the programmer discovers that because of the design of the application, it is necessary to make changes to each report to support the new printers. Which two design concepts most likely explain the situation? (Choose two.) (A) Inheritance SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 12 (B) Low cohesion (C) Tight coupling (D) High cohesion (E) Loose coupling F. Object immutablility

第24題 A company that makes Computer Assisted Design(CAD) software has, within its application some utility classes that are used to perform 3D rendering tasks. The company's chief scientist has just improved the performance of one of the utility classes' key rendering algorithms, and has assigned a programmer to replace the old algorithm with the new algorithm. When the programmer begins researching the utility classes, she is happy to discover that the algorithm to be replaced exists in only one class. The programmer reviews that class's API, and replaces the old algorithm with the new algorithm, being careful that her changes adhere strictly to the class's API. Once testing has begun, the programmer discovers that other classes that use the class she changed are no longer working properly. What design flaw is most likely the cause of there new bugs? (A) Inheritance (B) Tight coupling (C) Low cohesion (D) High cohesion (E) Loose coupling F. Object immutablility

第25題 Given: 1. class ClassA{ 2. public int numberOfInstances; 3. protected ClassA(int numberOfInstances){ 4. this.numberOfInstances = numberOfInstances; 5. } 6. } 7. class ExtendedA extends ClassA{ 8. private ExtendedA(int numberOfInstances){ 9. super(numberOfInstances); 10. } 11. public static void main(String[] args){ 12. ExtendedA ext = new ExtendedA(420); 13. System.out.print(ext.numberOfInstances); SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 13 14. } 15. } What is the result? (A) 420 is the output (B) An exception is thrown at runtime. (C) All constructors must be declared public. (D) Constructors CANNOT use the private modifier. (E) Constructors CANNOT use the protected modifier.

複選題第27題 Given: 10. class One{ 11. void foo(){} 12. } SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 14 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 */}

第28題 Given: 1. class X{ 2. X(){System.out.print(1);} 3. X(int x){ 4. this(); 5. System.out.print(2); 6. } 7. } 8. public class Y extends X{ 9. Y(){ 10. super(6); 11. System.out.print(3); 12. } 13. Y(int y){ 14. this(); 15. System.out.println(4); 16. } 17. public static void main(String[] a){new Y(5);} 18. } What is the result? (A) 13 (B) 134 (C) 1234 (D) 2134 (E) 2143 F. 4321

第29題 Given: SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 15 1. public class A{ 2. public void doit(){ 3. } 4. public String doit(){ 5. return "a"; 6. } 7. public double doit(int x){ 8. return 1.0; 9. } 10. } What is the result? (A) An exception is thrown at runtime. (B) Compilation fails because of an error in line 7. (C) Compilation fails because of an error in line 4. (D) Compilation succeeds and no runtime errors with class A occur.