Line 15 causes a stack overflow.
An exception is thrown at runtime.
The object referenced by a is eligible for garbage collection.
The object referenced by b is eligible for garbage collection.
The object referenced by a is not eligible for garbage collection.
The object referenced by b is not eligible for garbage collection.
第1题:
1. public class GoTest { 2. public static void main(String[] args) { 3. Sente a = new Sente(); a.go(); 4. Goban b = new Goban(); b.go(); 5. Stone c = new Stone(); c.go(); 6. } 7. } 8. 9. class Sente implements Go { 10. public void go() { System.out.println(”go in Sente.”); } 11. } 12. 13. class Goban extends Sente { 14. public void go() { System.out.println(”go in Goban”); } 15. } 16. 17. class Stone extends Goban implements Go { } 18. 19. interface Go { public void go(); } What is the result?()
第2题:
1. public class A { 2. void A() { 3. System.out.println(“Class A”); 4. } 5. public static void main(String[] args) { 6. new A(); 7. } 8. } What is the result?()
第3题:
1. class Pizza { 2. java.util.ArrayList toppings; 3. public final void addTopping(String topping) { 4. toppings.add(topping); 5. } 6. } 7. public class PepperoniPizza extends Pizza { 8. public void addTopping(String topping) { 9. System.out.println(”Cannot add Toppings”); 10. } 11. public static void main(String[] args) { 12. Pizza pizza = new PepperoniPizza(); 13. pizza.addTopping(”Mushrooms”); 14. } 15. } What is the result?()
第4题:
1. public class Test { 2. public static String output =””; 3. 4. public static void foo(int i) { 5. try { 6. if(i==1) { 7. throw new Exception(); 8. } 9. output += “1”; 10. } 11. catch(Exception e) { 12. output += “2”; 13. return; 14. } 15. finally { 16. output += “3”;17. } 18. output += “4”; 19. } 20. 21. public static void main(String args[]) { 22. foo(0); 23. foo(1); 24. 25. }26. } What is the value of the variable output at line 23?()
第5题:
1. class A { 2. public String toString () { 3. return “4”; 4. } 5. } 6. class B extends A { 7. public String toString () { 8. return super.toString() + “3”; 9. } 10. } 11. public class Test { 12. public static void main(String[]args) { 13. System.out.printIn(new B()); 14. } 15. } What is the result?()
第6题:
1. public class enclosingone ( 2. public class insideone{} 3. ) 4. public class inertest( 5. public static void main (string[]args)( 6. enclosingone eo= new enclosingone (); 7. //insert code here 8. ) 9. ) Which statement at line 7 constructs an instance of the inner class?()
第7题:
public class TestA{ public void methodA() throws IOException{ //…… } } public class TestB extends TestA{ public void methodA() throws EOFException{ //…… } } public class TestC extends TestA{ public void methodA() throws Exception{ //…… } } 当编译类TestC的时候,结果是哪项?()
第8题:
1. interface TestA { String toString(); } 2. public class Test { 3. public static void main(String[] args) { 4. System.out.println(new TestA() { 5. public String toString() { return “test”; } 6. } 7. } 8. } What is the result?()
第9题:
1. class Exc0 extends Exception { } 2. class Exc1 extends Exc0 { } 3. public class Test { 4. public static void main(String args[]) { 5. try { 6. throw new Exc1(); 7. } catch (Exc0 e0) { 8. System.out.println(“Ex0 caught”); 9. } catch (Exception e) { 10. System.out.println(“exception caught”); 11. } 12. } 13. } What is the result?()
第10题:
正常
编译错误
运行错误
以上都不对
第11题:
Line 15 causes a stack overflow.
An exception is thrown at runtime.
The object referenced by a is eligible for garbage collection.
The object referenced by b is eligible for garbage collection.
The object referenced by a is not eligible for garbage collection.
The object referenced by b is not eligible for garbage collection.
第12题:
InsideOnew ei= eo.new InsideOn();
Eo.InsideOne ei = eo.new InsideOne();
InsideOne ei = EnclosingOne.new InsideOne();
EnclosingOne.InsideOne ei = eo.new InsideOne();
第13题:
1. class TestA { 2. TestB b; 3. TestA() { 4. b = new TestB(this); 5. } 6. } 7. class TestB { 8. TestA a; 9. TestB(TestA a) { 10. this.a = a; 11. } 12. } 13. class TestAll { 14. public static void main (String args[]) { 15. new TestAll().makeThings(); 16. // ...code continues on 17. } 18. void makeThings() { 19. TestA test = new TestA(); 20. } 21. } Which two statements are true after line 15, before main completes?()
第14题:
1. class A { 2. public byte getNumber () { 3. return 1; 4. } 5. } 6. 7. class B extends A { 8. public short getNumber() { 9. return 2; 10. } 11. 12. public static void main (String args[]) { 13. B b = new B (); 14. System.out.printIn(b.getNumber()) 15. } 16. } What is the result?()
第15题:
class TestA { public void start() { System.out.println(”TestA”); } } public class TestB extends TestA { public void start() { System.out.println(”TestB”); } public static void main(String[] args) { ((TestA)new TestB()).start(); } } What is the result?()
第16题:
1. class Alpha { void m1() {} } 2. class Beta extends Alpha { void m2() { } } 3. class Gamma extends Beta { } 4. 5. class GreekTest { 6. public static void main(String [] args) { 7. a Alpha [] a = {new Alpha(), new Beta(), new Gamma() }; 8. for(Alpha a2 : a) { 9. a2.m1(); 10. if (a2 instanceof Beta || a2 instanceof Gamma) 11. //insert code here 12. } 13. } 14. } 哪一行代码插入到第11行,将编译但是会在运行时产生异常?()
第17题:
现有: class TestA { public void start() { System.out.println("TestA"); } } public class TestB extends TestA { public void start() { System.out.println("TestB"); } public static void main (string[] args) ( ((TestA)new TestB()).start(); ) } 运行结果是哪项?()
第18题:
1. class A { 3. public String to String() { 4. return “4”; 5. } 6. } 7. class B extends A { 8. public String toString() { 9. return super.toString() + “3”; 10. } 11. } 12. public class Test { 13. public static void main (String[] args) { 14. System.out.printIn(new B()); 15. } 16. } What is the result( )?
第19题:
1. public class test ( 2. public static void main(string args[]) { 3. int 1= 0; 4. while (i) { 5. if (i==4) { 6. break; 7. } 8. ++i; 9. } 10. 11. } 12. ) What is the value of i at line 10?()
第20题:
1. class Bar { } 1. class Test { 2. Bar doBar() { 3. Bar b = new Bar(); 4. return b; 5. } 6. public static void main (String args[]) { 7. Test t = new Test(); 8. Bar newBar = t.doBar(); 9. System.out.println(“newBar”); 10. newBar = new Bar(); 11. System.out.println(“finishing”); 12. } 13. } At what point is the Bar object, created on line 3, eligible for garbage collection?()
第21题:
new Inner(); // At line 3
new Inner(); // At line 8
new o.Inner(); // At line 8
new Outer.Inner(); // At line 8
第22题:
TeStA
TeStB
编译失败
运行时抛出异常
第23题:
a2.m2();
((Beta)a2).m2();
((Alpha)a2).m2();
((Gamma)a2).m2();
第24题:
Class A
Compilation fails.
An exception is thrown at line 2.
An exception is thrown at line 6.
The code executes with no output.