Java thread MCQ - Quiz

Q: In java, a thread can be created by ..........

Q: Predict the output:

class A implements Runnable{
      public void run(){
            try{
                  for(int i=0;i<4;i++){
                        Thread.sleep(100);
                        System.out.println(Thread.currentThread().getName());
                  }
            }catch(InterruptedException e){
            }
      }
}

public class Test{
      public static void main(String argv[]) throws Exception{
            A a = new A();
            Thread t = new Thread(a, "A");
            Thread t1 = new Thread(a, "B");
            t.start();
            t.join();
            t1.start();
      }
}

Q: What will be the output?

class A extends Thread{
      public void run(){
            for(int i=0; i<2; i++){
                  System.out.println(i);
            }
      }
}

public class Test{
      public static void main(String argv[]){
            Test t = new Test();
            t.check(new A(){});
      }
      public void check(A a){
            a.start();
      }
}

Q: What will happen when you attempt to compile and run the following code?

class A implements Runnable{
      public void run(){
            System.out.println("run-A");
      }
}

1. public class Test{
2.       public static void main(String argv[]){
3.             A a = new A();
4.             Thread t = new Thread(a);
5.             System.out.println(t.isAlive());
6.             t.start();
7.             System.out.println(t.isAlive());
8.       }
9. }

Q: Which of the following are methods of the Thread class?

1) yield()
2) sleep(long msec)
3) go()
4) stop()

Q: What notifyAll() method do?

Q: What will be the output after compiling and executing the following code?

public class Test implements Runnable{
      public static void main(String[] args) throws InterruptedException{
            Thread a = new Thread(new Test());
            a.start();
            System.out.print("Begin");
            a.join();
            System.out.print("End");
      }
    
      public void run(){
            System.out.print("Run");
      }
}

Q: What is the output for the below code?

class A implements Runnable{
      public void run(){
            System.out.println(Thread.currentThread().getName());
      }
}

1. public class Test{		
2.       public static void main(String... args){	
3.             A a = new A();
4.	       Thread t = new Thread(a);
5.	       t.setName("good");
6.	       t.start();
7.       }
8. }

Q: Which keyword when applied on a method indicates that only one thread should execute the method at a time.

Q: Given the code. What will be the result?

public class Test implements Runnable{
      public static void main(String[] args) throws InterruptedException{
            Thread a = new Thread(new Test());
            a.start();
        
            System.out.print("Begin");
            a.join();
            System.out.print("End");
      }
    
      public void run(){
            System.out.print("Run");
      }
}