a.wait();
t.wait();
t.join();
t.yield();
t.notify();
a.notify();
t.interrupt();
第1题:
1. public class X { 2. public static void main (String[]args) { 3. int [] a = new int [1] 4. modify(a); 5. System.out.printIn(a[0]); 6. } 7. 8. public static void modify (int[] a) { 9. a[0] ++; 10. } 11. } What is the result?()
第2题:
public class A extends Thread { A() { setDaemon(true); } public void run() { (new B()).start(); try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“A done”); } class B extends Thread { public void run() { try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“B done”); } } public static void main(String[] args) { (new A()).start(); } } What is the result?()
第3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4题:
5. class Order2 implements Runnable { 6. public void run() { 7. for(int x = 0; x 〈 4; x++) { 8. try { Thread.sleep(100); } catch (Exception e) { } 9. System.out.print("r"); 10. } } 11. public static void main(String [] args) { 12. Thread t = new Thread(new Order2()); 13. t.start(); 14. for(int x = 0; x 〈 4; x++) { 15. // insert code here 16. System.out.print("m"); 17. } } } 哪一个插入到第15行,最有可能产生输出 rmrmrmrm ?()
第5题:
1. class A implements runable ( 2. int i; 3. public void run () ( 4. try ( 5. thread.sleep(5000); 6. i= 10; 7. ) catch(InterruptedException e) {} 8. ) 9. ) 10. 11. public class Test { 12. public static void main (string args) ( 13. try ( 14. A a = new A (); 15. Thread t = new Thread (a); 16. t.start(); 17. 18. int j= a.i; 19. 20. ) catch (Exception e) {} 21. ) 22. ) Which statement al line 17 will ensure that j=10 at line 19?()
第6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7题:
Compilation will succeed for all classes and interfaces.
Compilation of class C will fail because of an error in line 2.
Compilation of class C will fail because of an error in line 6.
Compilation of class AImpl will fail because of an error in line 2.
第8题:
Compilation succeeds and 4 is printed.
Compilation succeeds and 43 is printed.
An error on line 9 causes compilation to fail.
An error on line 14 causes compilation to fail.
Compilation succeeds but an exception is thrown at line 9.
第9题:
Value is: 8
Compilation fails.
Value is: 12
Value is: -12
The code runs with no output.
An exception is thrown at runtime.
第10题:
a.wait();
t.wait();
t.join();
t.yield();
t.notify();
a.notify();
t.interrupt();
第11题:
Compilation succeeds and 4 is printed.
Compilation …………… is printed.
An error on line 9 cause compilation to fail.
An error on line 14 cause compilation to fail.
Compilation succeeds but an exception is thrown at line 9.
第12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.
第13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14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15题:
1. interface foo { 2. int k = 0; 3. } 4. 5. public class test implements Foo ( 6. public static void main(String args[]) ( 7. int i; 8. Test test = new test (); 9. i= test.k; 10.i= Test.k; 11.i= Foo.k; 12.) 13.) 14. What is the result?()
第16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17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18题:
The program runs and prints “0”
The program runs and prints “1”
The program runs but aborts with an exception.
An error “possible undefined variable” at line 4 causes compilation to fail.
An error “possible undefined variable” at line 9 causes compilation to fail.
第19题:
0
3
4
5
The code will not compile.
第20题:
Compilation fails.
Cannot add Toppings
The code runs with no output.
A NullPointerException is thrown in Line 4.
第21题:
a.wait();
t.wait();
t.join();
t.yield();
t.notify();
a.notify();
t.interrupt();
第22题:
Ex0 caught
exception caught
Compilation fails because of an error at line 2.
Compilation fails because of an error at line 6.
第23题:
Line 4 of class Target can be changed to return i++;
Line 2 of class Target can be changed to private int i = 1;
Line 3 of class Target can be changed to private int addOne() {
Line 2 of class Target can be changed to private Integer i = 0;
第24题:
Compilation succeeds.
An error at line 2 causes compilation to fail.
An error at line 9 causes compilation to fail.
An error at line 10 causes compilation to fail.
An error at line 11 causes compilation to fail.