第30題 Given: 1. public class SimpleCalc{ 2. public int value; 3. public void calculate(){value += 7;} 4. } And: 1. public class MultiCalc extends SimpleCalc{ 2. public void calculate(){value -= 3;} 3. public void calculate(int multiplier){ 4. calculate(); 5. super.calculate(); 6. value *= multiplier; 7. } 8. public static void main(String[] args){ 9. MultiCalc calculator = new MultiCalc(); 10. calculator.calculate(2); 11. System.out.println("Value is: " + calculator.value); 12. } 13. } What is the result?
(A) Value is: 8
(B) Compilation fails.
(C) Value is: 12
(D) Value is: -12
(E) The code runs with no output. F. An exception is thrown at runtime.

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.

第31題 Given: 1. public class Base{ 2. public static final String FOO = "foo"; 3. public static void main(String[] args){ 4. Base b = new Base(); 5. Sub s = new Sub(); 6. System.out.print(Base.FOO); 7. System.out.print(Sub.FOO); 8. System.out.print(b.FOO); 9. System.out.print(s.FOO); 10. System.out.print(((Base)s).FOO); 11. } 12. } 13. class Sub extends Base{public static final String FOO = "bar";} What is the result? (A) foofoofoofoofoo (B) foobarfoobarbar (C) foobarfoofoofoo (D) foobarfoobarfoo (E) barbarbarbarbar F. foofoofoobarbar G. foofoofoobarfoo

第35題 Given: 10. public class Hello{ 11. String title; 12. int value; SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 18 13. public Hello(){ 14. title += " World"; 15. } 16. public Hello(int value){ 17. this.value = value; 18. title = "Hello"; 19. Hello(); 20. } 21. } and: 30. Hello c = new Hello(5); 31. System.out.print(c.title); What is the result? (A) Hello (B) Hello World (C) Compilation fails. (D) Hello World 5 (E) The code runs with no output. F. An exception is thrown at runtime.

第37題 Given: 21. abstract class C1{ 22. public C1(){System.out.print(1);} 23. } 24. class C2 extends C1{ 25. public C2(){System.out.print(2);} 26. } 27. class C3 extends C2{ 28. public C3(){System.out.print(3);} 29. } 30. public class Ctest{ 31. public static void main(String[] a){new C3();} 32. } What is the result? (A) 3 (B) 23 (C) 32 (D) 123 (E) 321 F. Compilation fails. G. An exception is thrown at runtime.

複選題第38題 Given: 1. class One{ 2. public One foo(){return this;} 3. } 4. class Two extends One{ 5. public One foo(){return this;} 6. } 7. class Three extends Two{ 8. //insert method here 9. } Which two methods, inserted individually, correctly complete the Three class? (Choose two.) (A) public void foo(){} (B) public int foo(){return 3;} (C) public Two foo(){return this;} (D) public One foo(){return this;} (E) public Object foo(){return this;}

第39題 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. } Which four statments are true? (Choose four.) (A) Compilation fails. (B) An exception is thrown at runtime. (C) The attribute id in the ItemTest object remains unchanged. (D) The attribute id in the ItemTest object is modified to the new value. (E) A new ItemTest object is created with the preferred value in the id attribute.

第40題 SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 21 Given: 1. class Foo{ 2. private int x; 3. public Foo(int x){this.x = x;} 4. public void setX(int x){this.x = x;} 5. public int getX(){return x;} 6. } 7. 8. public class Gamma{ 9. static Foo fooBar(Foo foo){ 10. foo = new Foo(100); 11. return foo; 12. } 13. public static void main(String[] args){ 14. Foo foo = new Foo(300); 15. System.out.print(foo.getX() + "-"); 16. 17. Foo fooFoo = fooBar(foo); 18. System.out.print(foo.getX() + "-"); 19. System.out.print(fooFoo.getX() + "-"); 20. 21. foo = fooBar(fooFoo); 22. System.out.print(foo.getX() + "-"); 23. System.out.print(fooFoo.getX()); 24. } 25. } What is the output? (A) 300-100-100-100-100 (B) 300-300-100-100-100 (C) 300-300-300-100-100 (D) 300-300-300-300-100