单项选择题
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？（）
A. A done
B. B done
C. A done B done
D. B done A done
E. There is no exception that the application will print anything.
F. The application outputs “A done” and “B done”， in no guaranteed order.
相关考题
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单项选择题
public class X implements Runnable { private int x； private int y； public static void main（String [] args） { X that = new X（）； （new Thread（ that ））.start（）； （new Thread（ that ））.start（）； } public void run（） { for （；；） { synchronized （this） { x++； y++； } System.out.println（Thread.currentThread（）.getName（） + “x = “ + x + “， y = “ + y）； } } } What is the result？（）
A. Compilation fails.
B. The program prints pairs of values for x and y that might not always be the same on the same line （for example， “x = 2， y = 1”）.
C. The program prints pairs of values for x and y that are always the same on the same line （for example， “x = 1， y = 1”）. In addition， each value appears only once （for example， “x = 1， y = 1” followed by “x = 2， y = 2”）. The thread name at the start of the line shows that both threads are executing concurrently.
D. The program prints pairs of values for x and y that are always the same on the same line （for example， “x = 1， y = 1”）. In addition， each value appears only once （for example， “x = 1， y = 1” followed by “x = 2， y = 2”）. The thread name at the start of the line shows that only a single thread is actually executing. -
单项选择题
class MyThread extends Thread { public void run（） { System.out.println（“AAA”）； } public void run（Runnable r） { System.out.println（“BBB”）； } public static void main（String[] args） { new Thread（new MyThread（））.start（）； } } What is the result？（）
A. AAA
B. BBB
C. Compilation fails.
D. The code runs with no output. -
单项选择题
WhathappenswhenthreadXexecutesawait（）methodonobjectA，withoutowningobjectA’slock？（）
A. Compilation fails.
B. An exception is thrown.
C. The wait（） method has no effect.
D. Thread X receives the lock immediately.
E. Object A moves the thread to the wait pool.
