Dan's question on Thread

[Vad Fogel]

Question 14

class A extends Thread {
  private Object obj;
  public A(Object obj) {this.obj = obj;}
  public void run() {
    try {
      synchronized (obj) {obj.wait();}
    } catch (InterruptedException ie) {}
    System.out.print(Thread.currentThread().getName());
}}
class B {
  private void m1() {
    for (int i = 0; i < 10; i++) {
      A t1 = new A(this);
      t1.setName(String.valueOf(i));
      t1.setDaemon(true);
      t1.start();
    }
    synchronized (this) {notifyAll();}
  }
  public static void main(String[] args) {
    new B().m1();
}}

What are the possible results of attempting to compile and run the program?
a. All of the numbers 0 through 9 must always be printed
b. Some or all of the numbers 0 through 9 could be printed
c. There is no guarantee that anything will be printed
d. Run-time error

I chose c only, and that was wrong. I think, a possible result of the program's running is b indeed, but c is not a result, but rather a conclusion or concept. Anyway, the question itself is terrific , but since the number of correct choices is not shown, it was a bit confusing to me. :roll:

[Dan Chisholm]

Vad,
Thank you for all of the great feedback that you have been providing.
I agree that C is more of a statement of fact rather than a result. How would you feel about the following wording.

c. Nothing is printed.

[Vad Fogel]

Dan, it looks perfectly valid as a possible result now. At the same time, one could easily overlook the word possible in the question, but, well, the exam is meant to be tricky.