第42題 1. class A{ 2. public String doit(int x, int y){ 3. return "a"; 4. } 5. 6. public String doit(int... vals){ 7. return "b"; 8. } 9. } Given: 25. A a = new A(); 26. System.out.println(a.doit(4, 5)); What is the result?
(A) Line 26 prints "a" to System.out.
(B) Line 26 prints "b" to System.out.
(C) An exception is thrown at runtime.
(D) Compilation of class A will fail due to an error in line 6.

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

第41題 Given: 1. public class KungFu{ 2. public static void main(String[] args){ 3. Integer x = 400; 4. Integer y = x; 5. x++; 6. StringBuilder sb1 = new StringBuilder("123"); 7. StringBuilder sb2 = sb1; 8. sb1.append("5"); 9. System.out.println((x == y) + " " + (sb1 == sb2)); 10. } 11. } What is the result? SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 22 (A) true true (B) false true (C) true false (D) false false (E) Compilation fails. F. An exception is thrown at runtime.

第43題 Given: 1. class Plant{ 2. private String name; 3. public Plant(String name){this.name = name;} 4. public String getName(){return name;} 5. } 6. public class Tree extends Plant{ 7. public void growFruit(){} 8. public void dropLeaves(){} 9. } What statement is true? (A) The code will compile without changes. (B) The code will compile if public Tree(){Plant();} is added to the Tree class. SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 23 (C) The code will compile if public Plant(){Tree();} is added to the Plant class. (D) The code will compile if public Plant(){this("fern");} is added to the Plant class. (E) The code will compile if public Plant(){Plant("fern");} is added to the Plant class.

複選題第44題 Given: 1. class Employee{ 2. String name; double baseSalary; 3. public Employee(String name, double baseSalary){ 4. this.name = name; 5. this.baseSalary = baseSalary; 6. } 7. } 8. public class SalesPerson extends Employee{ 9. double commission; 10. public SalesPerson(String name, 11. double baseSalary, double commission){ 12. //insert code here 13. } 14. } Which two code fragments, inserted independently at line 12, will compile? (Choose two.) (A) super(name, baseSalary); (B) this.commission = commission; (C) super(); this.commission = commission; (D) this.commission = commission; super(); (E) super(name, baseSalary); this.commission = commission; F. this.commission = commission; super(name, baseSalary); G. super(name, baseSalary, commission);

複選題第45題 Given that: Gadget has-a Sprocket and Gadget has-a Spring and Gadget is-a Widget and SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 24 Widget has-a Sprocket Which two code fragments represent these relationships? (Choose two.) (A) class Widget{Sprocket s;} class Gadget extends Widget{Spring s;} (B) class Widget{} class Gadget extends Widget{Spring s1; Sprocket s2;} (C) class Widget{Sprocket s1; Spring s2;} class Gadget extends Widget{} (D) class Gadget{Spring s;} class Widget extends Gadget{Sprocket s;} (E) class Gadget{} class Widget extends Gadget{Sprocket s1; Spring s2;} F. class Gadget{Spring s1; Sprocket s2;} class Widget extends Gadget{}

第46題 Given: 10. public class Pizza{ 11. ArrayList toppings; 12. 13. public final void addTopping(String topping){ 14. toppings.add(topping); 15. } 16. 17. public void removeTopping(String topping){ 18. toppings.remove(topping); 19. } 20. } And: 30. class PepperoniPizza extends Pizza{ 31. public void addTopping(String topping){ 32. System.out.println("Cannot add Toppings"); 33. } 34. 35. public void removeTopping(String topping){ 36. System.out.println("Cannot remove pepperoni"); 37. } 38. } And: 50. Pizza pizza = new PepperoniPizza(); SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 25 51. pizza.addTopping("Mushrooms"); 52. pizza.removeTopping("Pepperoni"); What is the result? (A) Compilation fails. (B) Cannot add Toppings (C) The code runs with no output. (D) A NullPointerException is thrown in Line 4.

第48題 Given: 1. public class Venus{ 2. public static void main(String[] args){ 3. int[] x = {1, 2, 3}; 4. int y[] = {4, 5, 6}; 5. new Venus().go(x, y); 6. } 7. void go(int[]... z){ 8. for(int[] a : z) 9. System.out.print(a[0]); SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 26 10. } 11. } What is the result? (A) 1 (B) 12 (C) 14 (D) 123 (E) Compilation fails. F. An exception is thrown at runtime.

複選題第50題 Given: 1. public abstract class Shape{ 2. private int x; 3. private int y; 4. public abstract void draw(); 5. public void setAnchor(int x, int y){ 6. this.x = x; 7. this.y = y; 8. } 9. } Which two classes use the Shape class correctly? (Choose two.) (A) public class Circle implements Shape{ private in radius; } (B) public abstract class Circle extends Shape{ private in radius; } (C) public class Circle extends Shape{ private in radius; public void draw(); } (D) public abstract class Circle implements Shape{ private in radius; public void draw(); } (E) public class Circle extends Shape{ private in radius; public void draw(){/* code here */} } F. public abstract class Circle implements Shape{ private in radius; public void draw(){/* code here */} }