2011年JAVA认证模拟题第二阶段（19）
Q55.What is wrong with the following code?1. final class First {
2. private int a = 1;
3. int b = 2;
4. ｝
5. class Second extends First {
6. public void method() {
7. System.out.println(a+b);
8. ｝
9. ｝
a. You cannot invoke println() without passing it a string.
b. Because a is private, no classes other than First can access it.
c. Second cannot extend First.
d. final is not a valid keyword for a class.
Q56.What is displayed when the following piece of code is executed.
1. class Test extends Thread {
2. public void run() {
3. System.out.print(“1 “);
4. yield();
5. System.out.print(“2 “);
6. suspend();
7. System.out.print(“3 “);
8. resume();
2011年JAVA认证模拟题第二阶段（19）
</p> 9. System.out.print(“4 “);10. ｝
11 public static void main(String []args) {
12. Test t = new Test();
13. t.start();
14. ｝
15. ｝
a. Nothing, this is not a valid way to create and start a thread.
b. 1 2
c. 1 2 3
d. 1
Q57.What must be true for the RunHandler class so that the instances of RunHandler can be used as written in the following code?
1. class Test {
2. public static void main(String args[]){
3. Thread t = new Thread(new RunHandler());
4. t.start();
5. ｝
6. ｝
Select all valid answers ?
a. RunHandler must only implement the java.lang.Runnable interface.
b. RunHandler must only extend the Thread class.
c. RunHandler must extend the Thread class or implement Runnable interface.
d. RunHandler must provide a run() method declared as public and returning void.
55. c
56. b
57. cd
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