Subscribe

RSS Feed (xml)

Powered By

Skin Design:
Free Blogger Skins

Powered by Blogger

Tuesday, August 18, 2009

Java Quiz -6

Hi friends,

Today I would like to post few more questions to test your capability.
Dont worry guys, I will give you the answer too! Try to answer it yourself without referring to the answers to test yourself.

Q: 1 Given:
1. public class GC {
2. private Object o;
3. private void doSomethingElse(Object obj) { o = obj; }
4. public void doSomething() {
5. Object o = new Object();
6. doSomethingElse(o);
7. o = new Object();
8. doSomethingElse(null);
9. o = null;
10. }
11. }
When the doSomething method is called, after which line does the Object created in line 5 become
available for garbage collection?

A. Line 5
B. Line 6
C. Line 7
D. Line 8
E. Line 9
F. Line 10

Answer: D

Q: 2 Click the Exhibit button.
Which three code fragments, added individually at line 29, produce the output 100? (Choose three.)

A. n = 100;
B. i.setX( 100 );
C. o.getY().setX( 100 );
D. i = new Inner(); i.setX( 100 );
E. o.setY( i ); i = new Inner(); i.setX( 100 );
F. i = new Inner(); i.setX( 100 ); o.setY( i );

Answer: B, C, F

Q: 3 Given:
15. public class Yippee {
16. public static void main(String [] args) {
17. for(int x = 1; x < args.length; x++) {
18. System.out.print(args[x] + " ");
19. }
20. }
21. } and two separate command line invocations:
java Yippee
java Yippee 1 2 3 4
What is the result?

A. No output is produced.
1 2 3
B. No output is produced.
2 3 4
C. No output is produced.
1 2 3 4
D. An exception is thrown at runtime.
1 2 3
E. An exception is thrown at runtime.
2 3 4
F. An exception is thrown at runtime.
1 2 3 4

Answer: B

Q: 4 Given:
11. public void genNumbers() {
12. ArrayList numbers = new ArrayList();
13. for (int i=0; i<10; i++) {
14. int value = i * ((int) Math.random());
15. Integer intObj = new Integer(value);
16. numbers.add(intObj);
17. }
18. System.out.println(numbers);
19. }
Which line of code marks the earliest point that an object referenced by intObj becomes a candidate for
garbage collection?

A. Line 16
B. Line 17
C. Line 18
D. Line 19
E. The object is NOT a candidate for garbage collection.

Answer: D

Q: 5 Click the Exhibit button.
Given the fully-qualified class names:
com.foo.bar.Dog
com.foo.bar.blatz.Book
com.bar.Car
com.bar.blatz.Sun
Which graph represents the correct directory structure for a JAR file from which those classes can be
used by the compiler and JVM?

A. Jar A
B. Jar B
C. Jar C
D. Jar D
E. Jar E

Answer: A

Q: 6 A class games.cards.Poker is correctly defined in the jar file Poker.jar. A user
wants to execute the main method of Poker on a UNIX system using the command:
java games.cards.Poker
What allows the user to do this?

A. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java
B. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java/*.jar
C. Put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java/Poker.jar
D. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java
E. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java/*.jar
F. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java/Poker.jar

Answer: C

Q: 7 Given a class Repetition:
1. package utils;
2.
3. public class Repetition {
4. public static String twice(String s) { return s + s; }
5. }
and given another class Demo:
1. // insert code here
2.
3. public class Demo {
4. public static void main(String[] args) {
5. System.out.println(twice("pizza"));
6. }
7. }
Which code should be inserted at line 1 of Demo.java to compile and run Demo to print "pizzapizza"?

A. import utils.*;
B. static import utils.*;
C. import utils.Repetition.*;
D. static import utils.Repetition.*;
E. import utils.Repetition.twice();
F. import static utils.Repetition.twice;
G. static import utils.Repetition.twice;

Answer: F

Q: 8 Given:
11. public static void main(String[] args) {
12. String str = "null";
13. if (str == null) {
14. System.out.println("null");
15. } else (str.length() == 0) {
16. System.out.println("zero");
17. } else {
18. System.out.println("some");
19. }
20. }
What is the result?

A. null
B. zero
C. some
D. Compilation fails.
E. An exception is thrown at runtime.

Answer: D

Q: 9 Given:
11. static class A {
12. void process() throws Exception { throw new Exception(); }
13. }
14. static class B extends A {
15. void process() { System.out.println("B "); }
16. }
17. public static void main(String[] args) {
18. A a = new B();
19. a.process();
20. }
What is the result?

A. B
B. The code runs with no output.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 18.
F. Compilation fails because of an error in line 19.

Answer: F

Q: 10 Given:
11. public void testIfA() {
12. if (testIfB("True")) {
13. System.out.println("True");
14. } else {
15. System.out.println("Not true");
16. }
17. }
18. public Boolean testIfB(String str) {
19. return Boolean.valueOf(str);
20. }
What is the result when method testIfA is invoked?

A. True
B. Not true
C. An exception is thrown at runtime.
D. Compilation fails because of an error at line 12.
E. Compilation fails because of an error at line 19.

Answer: A

Hope you found this useful! Kindly give me your comments regarding the same.Many more Quizzes are yet to be posted! Kindly make use of them as much as possible!

2 comments:

anudeep said...

why u won't explain the answers ?

Chandrasekar said...

Hello Anudeep,

Try to compile the problem in your brain!
If it's dificult, please try to implement it in the textpad.

Practice makes people perfect!

Start implementing, stop expecting! My mentor's motto! :)