What is the output of the following code when compiled and run? Select two correct answers.
public class Question01 {
public static void main(String[] args){
int y=0; //line 1
int x=z=1; //line 2
System.out.println(y+","+x+","+z); //line 3
}
}
A. Prints 0,1,1
B. Error during compilation at line 1
C. Prints 0,0,1
D. Error during compilation at line 3
E. Error during compilation at line 2
Question 2. Select three correct statements.
A. The garbage collection thread cannot outlive the last user thread.
B. The garbage collection can be forced by invoking System.gc().
C. The garbage collection thread is a non-deamon thread.
D. The finalize() method is invoked at most once by the JVM for any given object.
E. The finalize() method may resurrect the object upon which it has been invoked.
What is the output of the following code when compiled and run? Select one correct answer.
import java.io.*;
public class Question05 {
public static void main(String[] args) {
Question05Sub myref = new Question05Sub();
try{
myref.test();
}catch(IOException ioe){}
}
void test() throws IOException{
System.out.println("In Question05");
throw new IOException();
}
}
class Question05Sub extends Question05 {
void test()throws IOException {
System.out.println("In Question05Sub");
}
}
A. Prints:
In Question05Sub
B. Prints:
In Question05
C. Prints:
In Question05
In Question05Sub
D. Prints:
In Question05Sub
In Question05
E. The code does not compile.
Select two correct statements about the code given below?
class A{}
class B extends A implements E{} //line 1
class C extends A{}
class D extends B{}
interface E{}
public class Question07 {
public static void main(String[] args) {
A a = new D(); //line 2
C c = new C(); //line 3
E e = (E)a; //line 4
B b = (B)e; //line 5
}
}
A. The code compiles without error and runs fine.
B. Compilation error on line 1 because interface E is not yet declared (forward-referencing).
C. Compilation error on line 4 because class A does not implement interface E.
D. The cast on line 4 is mandatory.
E. The cast on line 5 is not mandatory.
How many objects are eligible for garbage collection immediately after line 1? Select one correct answer.
public class Question08 {
public static void main(String[] args) {
Question08 q08 = new Question08();
q08.doSomething(); //line 1
Thread.sleep(20000);
}
public void doSomething(){
Object[] objArray = new Object[2];
for(int i=0;i<objArray.length;i++){
objArray[i] = new Object();
}
}
}
A. 0
B. 1
C. 2
D. 3
E. 4
What is the output of the following code when compiled and run? Select one correct answer.
public class Question09 {
public static void main(String[] args) {
try {
int i = (int)(Math.random()*10);
if(i<=5)
System.out.println("i = "+i);
else
throw new Exception("i > 5");
} catch (Exception e){
System.err.println(e.getMessage()+" (i="+i+")");
}
}
}
A. The output cannot be determined.
B. Compilation error.
C. An exception is thrown at runtime.
D. Output is i = 2
E. Output is i > 5 (i=6)
What is the output of the following code when compiled and run? Select one correct answer.
public class Question10 {
public static void main(String[] args) {
new Question10().doSomething();
}
public void doSomething(){
int i=5;
Thread t = new Thread(new Runnable(){
public void run(){
for(int j=0;j<=i;j++){
System.out.print(" "+j);
}
}
});
t.start();
}
}
A. Prints 0 1 2 3 4
B. Compilation error.
C. No output.
D. IllegalThreadStateException is thrown at runtime.
E. Prints 0 1 2 3 4 5
What is the output of the following code when compiled and run? Select one correct answer.
public class Question11 {
public static void main(String[] args) {
StringBuffer buf1 = new StringBuffer("Hello W");
addSomeStuff(buf1);
System.out.println(buf1.toString());
}
public static void addSomeStuff(StringBuffer buf){
StringBuffer b = buf.replace(6,10,"orld");
System.out.println(b.delete(0,1).toString());
}
}
A. Prints
Hello World
Hello World
B. Prints
Hello orld
Hello orld
C. Prints
Hello orld
ello orld
D. Prints
ello orld
ello orld
E. Compilation error.
What is the output of the following code when compiled and run? Select two correct answers. (Note: when an instance of a Vector is printed, its content appear between square brackets [])
import java.util.*;
public class Question13 {
public static void main(String[] args) {
Vector col = new Vector();
col.add(new Integer(1));
col.add(new Integer("2"));
col.add(new Float(3.2d)); //line 1
col.add(col.elementAt(1));
col.setElementAt(col.elementAt(2),0);
System.out.println(col);
}
}
A. Compilation error on line 1.
B. Only line 1 won't compile.
C. The code compiles and runs fine.
D. Prints [3.2, 2, 3.2, 2]
E. Prints [1, 2, 3.2, 2]
Select three correct statements.
A. A static method may override another static method.
B. A static method cannot override a non-static method.
C. A non-static method cannot override a static method.
D. A non-static method may be overloaded by a static method.
E. A synchronized method cannot be overridden.
public class Question01 {
public static void main(String[] args){
int y=0; //line 1
int x=z=1; //line 2
System.out.println(y+","+x+","+z); //line 3
}
}
A. Prints 0,1,1
B. Error during compilation at line 1
C. Prints 0,0,1
D. Error during compilation at line 3
E. Error during compilation at line 2
Question 2. Select three correct statements.
A. The garbage collection thread cannot outlive the last user thread.
B. The garbage collection can be forced by invoking System.gc().
C. The garbage collection thread is a non-deamon thread.
D. The finalize() method is invoked at most once by the JVM for any given object.
E. The finalize() method may resurrect the object upon which it has been invoked.
What is the output of the following code when compiled and run? Select one correct answer.
import java.io.*;
public class Question05 {
public static void main(String[] args) {
Question05Sub myref = new Question05Sub();
try{
myref.test();
}catch(IOException ioe){}
}
void test() throws IOException{
System.out.println("In Question05");
throw new IOException();
}
}
class Question05Sub extends Question05 {
void test()throws IOException {
System.out.println("In Question05Sub");
}
}
A. Prints:
In Question05Sub
B. Prints:
In Question05
C. Prints:
In Question05
In Question05Sub
D. Prints:
In Question05Sub
In Question05
E. The code does not compile.
Select two correct statements about the code given below?
class A{}
class B extends A implements E{} //line 1
class C extends A{}
class D extends B{}
interface E{}
public class Question07 {
public static void main(String[] args) {
A a = new D(); //line 2
C c = new C(); //line 3
E e = (E)a; //line 4
B b = (B)e; //line 5
}
}
A. The code compiles without error and runs fine.
B. Compilation error on line 1 because interface E is not yet declared (forward-referencing).
C. Compilation error on line 4 because class A does not implement interface E.
D. The cast on line 4 is mandatory.
E. The cast on line 5 is not mandatory.
How many objects are eligible for garbage collection immediately after line 1? Select one correct answer.
public class Question08 {
public static void main(String[] args) {
Question08 q08 = new Question08();
q08.doSomething(); //line 1
Thread.sleep(20000);
}
public void doSomething(){
Object[] objArray = new Object[2];
for(int i=0;i<objArray.length;i++){
objArray[i] = new Object();
}
}
}
A. 0
B. 1
C. 2
D. 3
E. 4
What is the output of the following code when compiled and run? Select one correct answer.
public class Question09 {
public static void main(String[] args) {
try {
int i = (int)(Math.random()*10);
if(i<=5)
System.out.println("i = "+i);
else
throw new Exception("i > 5");
} catch (Exception e){
System.err.println(e.getMessage()+" (i="+i+")");
}
}
}
A. The output cannot be determined.
B. Compilation error.
C. An exception is thrown at runtime.
D. Output is i = 2
E. Output is i > 5 (i=6)
What is the output of the following code when compiled and run? Select one correct answer.
public class Question10 {
public static void main(String[] args) {
new Question10().doSomething();
}
public void doSomething(){
int i=5;
Thread t = new Thread(new Runnable(){
public void run(){
for(int j=0;j<=i;j++){
System.out.print(" "+j);
}
}
});
t.start();
}
}
A. Prints 0 1 2 3 4
B. Compilation error.
C. No output.
D. IllegalThreadStateException is thrown at runtime.
E. Prints 0 1 2 3 4 5
What is the output of the following code when compiled and run? Select one correct answer.
public class Question11 {
public static void main(String[] args) {
StringBuffer buf1 = new StringBuffer("Hello W");
addSomeStuff(buf1);
System.out.println(buf1.toString());
}
public static void addSomeStuff(StringBuffer buf){
StringBuffer b = buf.replace(6,10,"orld");
System.out.println(b.delete(0,1).toString());
}
}
A. Prints
Hello World
Hello World
B. Prints
Hello orld
Hello orld
C. Prints
Hello orld
ello orld
D. Prints
ello orld
ello orld
E. Compilation error.
What is the output of the following code when compiled and run? Select two correct answers. (Note: when an instance of a Vector is printed, its content appear between square brackets [])
import java.util.*;
public class Question13 {
public static void main(String[] args) {
Vector col = new Vector();
col.add(new Integer(1));
col.add(new Integer("2"));
col.add(new Float(3.2d)); //line 1
col.add(col.elementAt(1));
col.setElementAt(col.elementAt(2),0);
System.out.println(col);
}
}
A. Compilation error on line 1.
B. Only line 1 won't compile.
C. The code compiles and runs fine.
D. Prints [3.2, 2, 3.2, 2]
E. Prints [1, 2, 3.2, 2]
Select three correct statements.
A. A static method may override another static method.
B. A static method cannot override a non-static method.
C. A non-static method cannot override a static method.
D. A non-static method may be overloaded by a static method.
E. A synchronized method cannot be overridden.
