Threads - Finding the output Questions and Answers

Sample11 is run - what will be the output?

public class Sample11
{
    public static void main(String[] args) throws InterruptedException
    {
        Thread t = new Thread(() ->
        {
            try
            {
                Thread.sleep(5000);
                System.out.println("finished");
            }
            catch (InterruptedException e)
            {
                System.out.println("interrupted");
            }
        });
        t.start();
        t.interrupt();
        t.join();
    }
}

Sample12 is run - what will be the output?

public class Sample12
{
    public static void main(String[] args)
    {
        System.out.println(Thread.currentThread().getName());
    }
}

Sample13 is run - what will be the output?

public class Sample13
{
    public static void main(String[] args)
    {
        Thread a = new Thread();
        Thread b = new Thread();
        System.out.println(a.getName() + " " + b.getName());
    }
}

Sample14 is run - what will be the output?

public class Sample14 extends Thread
{
    Sample14()
    {
        super("loader");
    }

    public void run()
    {
        System.out.println(getName());
    }

    public static void main(String[] args) throws InterruptedException
    {
        new Sample14().start();
    }
}

Sample15 is run - what will be the output?

public class Sample15
{
    public static void main(String[] args) throws InterruptedException
    {
        Thread t = new Thread(() ->
        {
            throw new RuntimeException("boom");
        });
        t.start();
        t.join();
        System.out.println("main done");
    }
}

Sample16 is run - what will be the output?

public class Sample16
{
    public static void main(String[] args) throws InterruptedException
    {
        Thread t = new Thread(() -> { throw new RuntimeException("x"); });
        try
        {
            t.start();
            t.join();
        }
        catch (RuntimeException e)
        {
            System.out.println("caught");
        }
        System.out.println("end");
    }
}

Sample17 is run - what will be the output?

public class Sample17
{
    public static void main(String[] args) throws InterruptedException
    {
        Thread t = new Thread(() -> System.out.println(10 / 0));
        t.setUncaughtExceptionHandler(
                (thread, ex) -> System.out.println("handled " + ex.getClass().getSimpleName()));
        t.start();
        t.join();
    }
}

Sample18 is run - what will be the output?

public class Sample18
{
    public static void main(String[] args)
    {
        new Thread(() -> System.out.println("A")).start();
        new Thread(() -> System.out.println("B")).start();
    }
}

Sample19 is run - what will be the output?

public class Sample19
{
    static int count = 0;

    public static void main(String[] args) throws InterruptedException
    {
        Runnable r = () -> { for (int i = 0; i < 10000; i++) count++; };
        Thread a = new Thread(r), b = new Thread(r);
        a.start(); b.start();
        a.join(); b.join();
        System.out.println(count);
    }
}

Sample20 is run - what will be the output?

public class Sample20
{
    static volatile long total = 0;

    static class Adder extends Thread
    {
        public void run()
        {
            for (int i = 0; i < 50000; i++) total++;
        }
    }

    public static void main(String[] args) throws InterruptedException
    {
        Adder x = new Adder(), y = new Adder();
        x.start(); y.start();
        x.join(); y.join();
        System.out.println(total);
    }
}