80. Given: 

3. interface Fish{}

 4. class Perch implements Fish{} 

5. class Walleye extends Perch{} 

6. class Bluegill{} 

7. public class Fisherman {

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

9. Fish f = new Walleye()； 

10. Walleye w = new Walleye() 

11. Bluegill b = new Bluegill()； 

12. if(f instanceof Perch) System.out.print("f-p ")； 

13. if(w instanceof Fish) System.out.print("w-f ")； 

14. if(b instanceof Fish) System.out.print("b-f ")； 

15. } 

16. } 

What is the result?
(A) w-f
(B) f-p w-f
(C) w-f b-f
(D) f-p w-f b-f
(E) Compilation fails.

75. Given: 11. public interface A{ public void m1()； } 13. class B implements A{ } 14. class C implements A{ public void m1(){}} 15. class D implements A{ public void m1(int x){}} 16. abstract class E implements A {} 17. abstract class F implements A { public void m1(){} } 18. abstract class G implements A { public void m1(int x){} } What is the result? (A) Compilation succeeds. (B) Exactly one class does NOT compile. (C) Exactly two classes do NOT compile. (D) Exactly four classes do NOT compile. (E) Exactly three classes do NOT compile.

76. Given: 1. class TestA{ 2. public void start(){System.out.println("TestA")；} 3. } 4. public class TestB extends TestA{ 5. public void start(){System.out.println("TestB")；} 6. public static void main(String[] args){ 7. ((TestA)new TestB()).start()； 8. } 9. } What is the result? (A) TestA (B) TestB (C) Compilation fails. (D) An exception is thrown at runtime.

77. Given: 11. public static void main(String[] args) {  12. Object obj = new int{1, 2, 3}； 13. int[] someArray = (int[])obj； 14. for (int i: someArray) System.out.print(i + " ")； 15. } What is the result? (A) 1 2 3 (B) Compilation fails because of an error in line 12. (C) Compilation fails because of an error in line 13. (D) Compilation fails because of an error in line 14. (E) A ClassCastException is thrown at runtime.

79. Given classes defined in two different files: 1. package packageA； 2. public class Message{ 3. String getText(){return "text"；} 4. } And: 1. package packageB； 2. public class XMLMessage extends packageA .Message{ 3. String getText(){return "＜msg＞text＜/msg＞"；} 4. public static void main(String[] args) { 5. System.out.println(new XMLMessage().getText())； 6. } 7. } What is the result of executing XMLMessage.main? (A) text (B) Compilation fails. (C) ＜msg＞text＜/msg＞ (D) An exception is thrown at runtime.

81. Given: 1. interface DoStuff2{ 2. float getRange(int low, int high)；}  3. 4. interface DoMore { 5. float getAvg(int a, int b, int c)；} 6. 7. abstract class DoAbstract implements DoStuff2, DoMore{} 8. 9. class DoStuff implements DoStuff2{ 10. public float getRange(int x, int y){return 3.14f；}} 11. 12. interface DoAll extends DoMore{ 13. float getAvg(int a, int b, int c, int d)；} What is the result? (A) The file will compile without error. (B) Compilation fails. Only line 7 contains an error. (C) Compilation fails. Only line 12 contains an error. (D) Compilation fails. Only line 13 contains an error. (E) Compilation fails. Only lines 7 and 12 contain errors. F. Compilation fails. Only lines 7 and 13 contain errors. G. Compilation fails. Lines 7, 12, and 13 contain errors.

82. Given: 11. public interface A111{ 12. String s = "yo"； 13. public void method1()；14. } 17. interface B{} 20. interface C extends A111, B{ 21. public void method1()； 22. public void method1(int x)； 23. } What is the result? (A) Compilation succeeds. (B) Compilation fails due to multiple errors. (C) Compilation fails due to an error only on line 20. (D) Compilation fails due to an error only on line 21. (E) Compilation fails due to an error only on line 22.

84. Given: 11. class Alpha{ 12. public void foo(){System.out.print("Afoo ")；} 13. } 14. public class Beta extends Alpha{ 15. public void foo(){System.out.print("Bfoo ")；} 16. public static void main(String[] args){ 17. Alpha a = new Beta()； 18. Beta b = (Beta)a； 19. a.foo()；20. b.foo()； 21. } 22. } What is the result? (A) Afoo Afoo (B) Afoo Bfoo (C) Bfoo Afoo (D) Bfoo Bfoo (E) Compilation fails.

85. Given: 11. class Animal{public String noise(){return "peep"；}} 12. class Dog extends Animal{ 13. public String noise(){return "bark"；} 14 } 15. class Cat extends Animal{ 16. public String noise(){return "meow"；} 17. } ... 30. Animal animal = new Dog()； 31. Cat cat = (Cat)animal；32. System.out.println(cat.noise())； What is the result? (A) peep (B) bark (C) meow (D) Compilation fails. (E) An exception is thrown at runtime.

87. A team of programmers is involved in reviewing a proposed design for a new utility class, After some discussion, they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself. What design issue has the team discovered? (A) Tight coupling (B) Low cohesion (C) High cohesion (D) Loose coupling (E) Weak encapsulation

複選題89. Given: 1. public class Car{ 2. private int wheelCount； 3. private String vin； 4. public Car(String vin){ 5. this.vin = vin； 6. this.wheelCount = 4； 7. } 8. public String drive(){ 9. return "zoom-zoom"； 10. } 11. public String getInfo(){ 12. return "VIN: " + vin + "wheels: " + wheelCount； 13. } 14. } And: 1. public class MeGo extends Car{ 2. public MeGo(String vin){ 3. this.wheelCount = 3； 4. } 5. } What two must the programmer do to correct the compilation errors? (Choose two.) (A) insert a call to this() in the Car constructor (B) insert a call to this() in the MeGo constructor (C) insert a call to super() in the MeGo constructor (D) insert a call to super(vin) in the MeGo constructor (E) change the wheelCount variable in Car to protected