JAVA THREADS QUIZ

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. }

null

good

None of these

Compilation succeed but Runtime Exception

Compilation fails with an error at line 5

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Compilation fails with an error at line 6

run-a run-a

Compilation succeed but Runtime Exception

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

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

An exception is thrown at runtime.

Compilation fails.

"go" is printed

"gogo" is printed

"gogogo" is printed

TRUE ANSWER : ?
YOUR ANSWER : ?

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

native

synchronized

volatile

final

static

TRUE ANSWER : ?
YOUR ANSWER : ?

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"); }}

"BeginRunEnd" is printed.

"BeginEnd" is printed.

An exception is thrown at runtime.

Compilation fails.

"BeginEndRun" is printed.

TRUE ANSWER : ?
YOUR ANSWER : ?

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(); }}

Compilation error, class A has no start method

0 1

Compilation succeed but runtime exception

None of these

0 0

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following constructor of class Thread is valid one?

Thread(Runnable threadOb, String threadName)

Thread(String threadName, int priority)

Thread(int priority)

Thread(Runnable threadOb, int priority)

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Predict the output:public class Test extends Thread{ private int i; public void run(){ i++; } public static void main(String[] args){ Test a = new Test(); a.run(); System.out.print(a.i); a.start(); System.out.print(a.i); }}

Prints

IllegalThreadStateException is thrown

Prints

Compiler error

Prints

TRUE ANSWER : ?
YOUR ANSWER : ?

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); } }}

Clean compile but no output at runtime

A run 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

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

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

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.

TRUE ANSWER : ?
YOUR ANSWER : ?