JAVA THREADS QUIZ

In java a thread can be created by ..........

Both of the above

Implementing Runnable interface.

None of these

Extending the thread class.

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What will happen after compiling and running following code?class A implements Runnable{ public void run(){ System.out.println("run-a"); }}1. public class Test{2. public static void main(String... args){3. A a = new A();4. Thread t = new Thread(a);5. t.start();6. t.start();7. }8. }

run-a run-a

Compilation fails with an error at line 6

Compilation succeed but Runtime Exception

None of these

run-a

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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. }

false run-A true

Compilation fails due to an error on line 7

false run-A false

None of these

true run-A true

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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. }

None of these

Compilation fails with an error at line 5

good

Compilation succeed but Runtime Exception

null

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What is the output for the below code ?public class Test extends Thread{ public static void main(String argv[]){ Test t = new Test(); t.run(); } public void start(){ for(int i = 0; i < 10; i++){ System.out.println("Value of i = " + i); } }}

A run time error indicating that no run method is defined for the Thread class

None of these

Clean compile but no output at runtime

A compile time error indicating that no run method is defined for the Thread class

Clean compile and at run time the values 0 to 9 are printed out

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Analyze the following code:public class Test implements Runnable{ public static void main(String[] args){ Test t = new Test(); t.start(); } public void run() { }}

The program does not compile because the start() method is not defined in the Test class.

The program compiles, but it does not run because the run() method is not implemented.

The program compiles, but it does not run because the start() method is not defined.

The program compiles and runs fine.

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What notifyAll() method do?

Wakes up all threads that are not waiting on this object's monitor

Wakes up all threads that are waiting on this object's monitor

None of these

Wakes up one threads that are waiting on this object's monitor

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Analyze the following code:public class Test implements Runnable{ public static void main(String[] args){ Test t = new Test(); } public Test(){ Thread t = new Thread(this); t.start(); } public void run(){ System.out.println("test"); }}

The program has a compilation error because t is defined in both the main() method and the constructor Test().

The program compiles fine, but it does not run because you cannot use the keyword this in the constructor.

The program compiles and runs and displays nothing.

The program compiles and runs and displays test.

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What will be the output of the following program code?public class Test implements Runnable{ public static void main(String[] args){ Thread t = new Thread(this); t.start(); } public void run(){ System.out.println("test"); }}

None of these

The program compiles fine, but it does not print anything because t does not invoke the run() method

The program does not compile because this cannot be referenced in a static method.

The program compiles and runs fine and displays test on the console.

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Analyze the following code:public abstract class Test implements Runnable{ public void doSomething() { };}

The program will not compile because it does not implement the run() method.

The program will not compile because it does not contain abstract methods.

None of these

The program compiles fine.

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