Integer int question

Fri, 9 May 2008 05:50:58 MDT

source:http://enigma.vm.bytemark.co.uk/webstart.html
John Meyers's SCJP 5 mock exam:question 7

code:


class test {
 public static void main(String[] args) {
 test inst_test = new test();
 int i1 = 2000;
 int i2 = 2000;
 int i3 = 2;
 int i4 = 2;
 Integer Ithree = new Integer(2); // 1
 Integer Ifour = new Integer(2); // 2
 System.out.println( Ithree == Ifour );
 inst_test.method( i3 , i4 );
 inst_test.method( i1 , i2 );
 }
 public void method( Integer i , Integer eye ) {
 System.out.println(i == eye );
 }
}

Answe...

Regd Multiple choice question pattern

Fri, 9 May 2008 04:50:59 MDT

Hi
i have a doubt rerd multiple choice question type for SCJP1.5 exam
is it mentioned clearly in each question how any answers are correct or
just written choose all that apply (like k&B style) please help

Explaint the ouput...

Fri, 9 May 2008 04:50:58 MDT

public class T6
{
public static void main(String[] args)
{
long intBig = Integer.MAX_VALUE + 1;
long longBig = Integer.MAX_VALUE + 1L;
if(intBig==longBig){
System.out.println("True");
}else{
System.out.println("False");
}
}
}

It's output is False. how the output is coming.

Class finalization

Fri, 9 May 2008 01:50:57 MDT

code:


src:http://technoheads.blogspot.com/
 
Class finalization can be done by implementing the following method:static void classFinalize() throws Throwable;True Or False?
(1)True
(2)False
Answer : 2
Explanation : PREVIOUSLY: If a class declares a class method classFinalize that takes no arguments and returns no result: static void classFinalize() throws Throwable { . . . } then this method will be invoked before the class is unloaded . Like thefinalize method for objects, this method will be automatically invoked only once. This method may optionally be declared private, protected, or public. NOW: Class finalization has been removed from the Java language. Thefunctionality of JLS 12....

Sylabus for SCJP 1.6

Fri, 9 May 2008 01:16:57 MDT

Hi,

I am preparing for SCJP 1.6, but have the book Khalid Mughal 1.4, so going through the topics like Collection, Threading, Exception Handeling, Garbage collection of 1.4 currently. I want to know that what topics are added so far(from scjp 1.4) in 1.6 exam and what topics are excluded. Can somebody please help so that i can arrange those topics from somewhere?

abstract interface

Fri, 9 May 2008 00:54:57 MDT

I found that it is legal to declare a interface as abstract.
Is there any advantage in declaring a interface as abstract. We all know that all method in interface are implicitly abstract. will this declaration make any difference in the interface?

Chapter 6 Self Test Q1

Fri, 9 May 2008 00:08:57 MDT

import java.util.regex.*;
class Regex2
{
public static void main(String[] args)
{
Pattern p = Pattern.compile(args[0]);
Matcher m = p.matcher(args[1]);
boolean b = false;
while(b = m.find())
{
System.out.print(m.start() + m.group());
}
}
}
And the command line:
java Regex2 "\d*" ab34ef

What is the result?
A. 234
B. 334
C. 2334
D. 0123456
E. 01234456
F. 12334567
G. Compilation fails.

Answer is E but i am not getting this please explain me.

please advice.

Thu, 8 May 2008 17:16:56 MDT

I am looking forward to appear for SCJP 1.5 in a month or so. I am done with Head First Java by Kathy and Bert. It has been a smooth journey till now( thanks to Kathy and Bert!). What should be the next step in my preparation? I see there is a SCJP Study Guide by Kathy and Berts avalaible and also there is an Exam Simulator from Whizlabs. What would be a good choice? I am a beginner.

Question

Thu, 8 May 2008 14:54:56 MDT

code:


src:
http://technoheads.blogspot.com/ (http://technoheads.blogspot.com/)
class test
{
public static void main(String[] args) 
{
test inst_test = new test();
int i1 = 2000;
int i2 = 2000;
int i3 = 2;
int i4 = 2;
Integer Ithree = new Integer(2); // 1
Integer Ifour = new Integer(2); // 2
System.out.println( Ithree == Ifour );
inst_test.method( i3 , i4 );
inst_test.method( i1 , i2 );
 
}
public void method( Integer i , Integer eye )
{
System.out.println(i == eye );
}
}
 
a. true false true
b. false true false
c. false false false
d. true true false
e. Compile error
 


Getting SCJP...
Thu, 8 May 2008 11:08:55 MDT
I want to be a web developer but most all my experience is in systems integration and administration. That said most employers overlook my resume when filling a development position.
 
Will an SCJP help to change the direction of my career? Once I achieve the SCJP I would move on to the SCJD as well. At least that is my current thinking. What does everyone think?
 
Higgledy


final objects in the enhanced loop
Thu, 8 May 2008 10:34:55 MDT
Hi,
 
I was wondering why can we use the word "final" before the object in the enhanced loop? I mean something like:
 

for(final someObject : someArray)
...
 

We will use someObject to go through the whole array so we will definitely change this reference. Why the final word is allowed here?


StackOverflowException
Thu, 8 May 2008 10:18:56 MDT
Consider the following method from jqplus6:
 
 quote:

int factorial(int n)
{
 if(n==1)
 {
 return 1;
 }
 else
 {
 return n*factorial(n-1);
 }
}

 

According to the answer given in the evaluation this method, if called with a very big integer, will throw StackOverflowException. I understand the concept that stands beyond that but I was wondering if we will always get the StackOverflowException?
 
I mean does the JVM has some fixed amount of memory reserved or it is dependant of the system? Can we theoretically, having lots of memory and operating system ready to give it to the JVM, finish to perform thi...


short and Integer
Thu, 8 May 2008 09:54:55 MDT
Consider the following code:
 
 quote:

public class TestClass
{
 public static void main(String[] args)
 {
 short s = 9;
 Integer i = 9;
 System.out.println( s == i );
 }
}

 

This actually compiles and prints "true".
For me it seems like code that should not compile..
 
What actually happend there?


Integer.MIN_VALUE
Thu, 8 May 2008 09:32:55 MDT
Consider the following code from jqplus6:
 
 quote:

public class TestClass
{
 public static void main(String[] args) throws Exception
 {
 int a = Integer.MIN_VALUE;
 int b = -a;
 System.out.println( a+ " "+b);
 }
}

 

It will print two same negative numbers.
 
Why????


Java Language Specification for Java 6
Thu, 8 May 2008 09:26:55 MDT
Hi,
 
I downloaded JLS Third Edition but I'm not sure if it is up to date for Java 6?
 

Is there any difference between Java 5 and Java 6 in the language itself (not counting the libraries)?


Serialization is not for Statics... Why??
Thu, 8 May 2008 08:54:55 MDT
Hi all
Can anyone explain me in detail why serialization cannot be applied to static variables. I have gone through K&B book but couldn't understand... Please help !
 
Thanks


Re take option
Thu, 8 May 2008 06:54:55 MDT
Hi there, I've got one voucher for the exam with retake option, in case I failed it how long would I have to re take it?.. is there any standard date?... or I would be schedule it within several months?... thanks.


private constructor in abstract classes
Thu, 8 May 2008 03:04:55 MDT
I tried to create private constructor in abstract classes.
It is allowing.
 
What is the use of private condtructors in absract claases?


HELP ME!
Thu, 8 May 2008 02:28:54 MDT
Hi 
 I have planned to write SCJP 1.5 this month end..i dont have much time to prepare as i'm working in a s/w concern... so, how can i prepare ? do we have any website for faq for SCJP?please do help me


Garbage Collection
Thu, 8 May 2008 00:32:54 MDT
code:

Src:http://devesh2k1.googlepages.com/home
 
How many objects will be eligible for GC just after the method returns?
public void compute(Object p)
{
 Object a = new Object();
 int x = 100;
 String str = "abc";
}
Answer: 1
Explanation: Objects passed to the method are never garbage collected in (or right after) that method. So p cannot be GCed. x is not an object. "abc" is a string literal which goes to the string pool and is not GCed. So, only a is eligible for GC.
-----------
 
what about the String. Str is also garbage collected, so answer should be 2.



operators
Wed, 7 May 2008 22:42:54 MDT
I hava problem in following
 
class A{
 public static void main(String args[]){
 byte b=-1,c,d;
 c=(byte)(b>>>1);
 d=(byte)(b>>>25);
 System.out.print(c+","+d);
 }
}
according to my knowlage that result is 127,127
but actually printed -1,127 
would you slove this problem?


Help
Wed, 7 May 2008 19:54:54 MDT
Hi everyone, I am going to take SCJP5.0 exam on 24th this month, please help me by providing mock exam and dump materials. Thank you to all.


Coupling question
Wed, 7 May 2008 11:46:53 MDT
Hi there, I have problems understanding the coupling topic expectations for the exam (SCJP 1.5), is there any good examples that could illustrate this concept and what is the exam expecting us to know?, thanks in advance.


volatile keyword
Wed, 7 May 2008 07:42:52 MDT
Can anyone the practical usage of 'volatile' keyword comparing it with 'synchronized' keyword with an example?


15 min survey in the certification exam
Wed, 7 May 2008 07:32:52 MDT
Hi there, I have been told that when you first take the exam you have to ask a survey about how good you are in the different topics on the exam, my question is, does the exam get harder the more you answer you're good on the topics?.. thanks.


Project
Wed, 7 May 2008 07:00:52 MDT
Hello,
 
I'm preparing to take the SCJP and i read some books about it. But what i really lack is some experience with the language. So, what i'm asking for is... can you guys me an idea about a project (something similar to SCJD i think) so i can work on it? Thanks...


reg Questions for sun's scjp exam
Wed, 7 May 2008 03:08:52 MDT
I mean to ask once they prepare a set Questions for the scjp exam in the database.How often they change the Questions in the database.Because each individual should be tested on the same level of Questions.


plz help me
Wed, 7 May 2008 02:52:52 MDT
I want to give scjp1.6
but i don't have mock exam....can anybody tell me which is best or give me sites where i buy it plzzzzzzzzzzz


Inner Classes and GC
Wed, 7 May 2008 02:22:51 MDT
Hello folks,
i have a short question about Inner Classes and GC.
 
Given:
 
code:
MyOuter.MyInner inner = new MyOuter().new MyInner();
inner = null;

 
Are 2 objects eligable for gc after setting the reference variable to null or is there something special? 
 
Thanks,
Frank Hinkel


Not yet received SCJP 5 certificate from past 6 months
Wed, 7 May 2008 01:32:51 MDT
Hi ranchers,
 
I have taken SCJP 5 exam on Nov 17th 2007 and I have not yet received the certificate from Sun. I have registered in http://www.certmanager.net/sun (http://www.certmanager.net/sun) and I could see all my certification details there. I have mailed to the following email addresses many times.
1. Sun Certification Support <certification@educationservicesgroup.com>
2. who2contact@sun.com
3. fulfillment@prometric.com
 
I got reply from 
Sun Certification Support<certification@educationservicesgroup.com> 2 times once in January and once again in March saying that it will be resent within 4 weeks. But I have not received it. My address details are also c...


Object creation for Integer class
Tue, 6 May 2008 23:54:51 MDT
1. Integer i1=new Integer(127);
2. Integer i2=new Integer(127);
 
Here only one object is being created. If the parameter value is greater 127 it creates two objects though the values passed are same. Why it is so?


Assignments
Tue, 6 May 2008 23:50:51 MDT
1. final int i=127;
2. byte b=i;
 
This piece of code works...
 
1. final int i;
2. i=127;
3. byte b=i;
 
This piece of code is not working.
 
What is the difference in the above two pieces of code?


FINAL VARIABLE DECLARATION
Tue, 6 May 2008 23:44:51 MDT
1. final int i=127;
2. final int i;
 i=127;
 
What is the difference in the two decalrations?


What happens when we print null character 'u0000' ?
Tue, 6 May 2008 17:16:50 MDT
HI
I am finding it strange when I am trying to print default value of char type.
 
public class AClass {
 
 
 public static void main(String[] args) {
 char c='\u0000';
 System.out.println("c is "+c);
\\IT is working like I have written System.exit(0) here
 System.out.println("after print ");
 
 }
}


Casting with Arrays that hold objects references
Tue, 6 May 2008 11:54:50 MDT
Hi,
 

I'm have this main method:
 
public static void main(String[] args) {

Object[] o1 ={"xxxxx","yyyyy",};
Object[] o2=new String[]{"xxxxx","yyyyy",};

String[] s2=(String[])o2; //run fine
String[] s1=(String[])o1; //throws ClassCastException

}
It's code compile fine but throws ClassCastException. 
 
Why? What's the difference between objects o1 and o2?
 
Thanks!!!!!


I didnt recieve my certification account until now!!!
Tue, 6 May 2008 11:20:50 MDT
hello mates,
 
i've posted here before for the same subject, but this time it took a longer time, why Sun didnt send to me the certification database account until now???? you told me to be patient but until when??? its been a week and i have no idea what is happening, a friend of mine took the SCJP and recieved his account information after 1 or 2 days, please i need you advice.


Serialization
Tue, 6 May 2008 11:14:50 MDT
Hi guys,
 
Given:
 
code:
class Animal implements Serializable()
{ private Eyes eyes;
 private Ears ears;
 ...
}

 
code:
class Dog extends Animal()
{
 private Legs legs;
 ...
}

 
When I serialize a dog Object how many objects ars serialized?
dog + legs + eyes + ears = 4 objects?
is this right?
 
Thank you
Arsineh


Is SCJP 1.4 still alive?
Tue, 6 May 2008 08:50:49 MDT
Hi,
 
Just wanted to know, whether SCJP 1.4 is still continuing or it's no more now?
 
If yes then please provide the link, as I was not able to find link on SUN's Offcial Site (http://www.sun.com).
 
 
 
Thanks


Confused...
Tue, 6 May 2008 06:12:49 MDT
I am Currently Preparing for SCJP and will complete it within 3 months.
I have done BSC CompSci. I have no work Experience in the field of Software Development, So looking forward to step in Development field.
 
I am very confused how do I go along with Java as we all know Java is moving at an tremendous Pace.In each new release there are loads of new features emerging out.New Techniques and Services are coming out every now and then.
 
As a Novie in the world of Java, can any one suggest me the proper guide lines or path how do we stay back to back with Java.
 
Also Do let me know, List all the services and technologies (Related to or Not Related to Java) one should know if he/she plans to go ahead with J...


What is the difference between null and void?
Tue, 6 May 2008 04:42:49 MDT
Anyone knows?
 
I mean also the physical difference - like reserved space in the memory, consequences, what can we do with null that we cannot do with void and vice versa....


SCJP Exam
Tue, 6 May 2008 04:12:49 MDT
Hi,
 
Which exam should I go for 5.0 or 6.0 and why? Please can anybody tell me what is the difference between 5.0 and 6.0?
 
Thanks,
Sukhjot


Collection.toArray() method
Tue, 6 May 2008 03:20:49 MDT
Hi.
 
I have this code:
 
public class Test3 {
 public static void main(String [] args) {
 LinkedList<String> list = new LinkedList<String>();
 list.add("one "); list.add("two "); list.add("three ");
 String [] sa = new String[3];
 sa = (String []) list.toArray(); // insert code here
 for(String s : sa)
 System.out.print(s);
 }
 }
 
If I run this class I get a ClassCastException.
 
Why?


garbage collection?
Tue, 6 May 2008 02:22:48 MDT
code:
 
public Object m(){//10
 Object o = new Float(3.14F);//11
 Object[] oa = new Object[1];//12
 oa[0] = 0;//13
 o = null;//14
 return oa[0];//15
}
when is the Float object,created in line 11,eligible for garbage collection?
A Just after line 13
B Just after line 14
C Never in this method.
D Just after line 15 (that is,at the mehod returns)
Answer:B

 
I thought the answer would be D,because oa[0] still refer to the Float Object after line 14,it's not eligible for garbage collection.


Garbage collection question
Tue, 6 May 2008 02:00:48 MDT
Hello everyone.
 
This is a question from Sun's Free Mock Test::
--------
Given:
public class Test3 {
static long story;
 
public static void main(String[] args) {
if (story == 0) {
Long tale = 343L;
story = go(tale);
}
// do stuff -- line 8
System.out.print(story);
}
 
static long go(Long t) {
return t++;
}
}
Which is true?
--------
and the correct answer is: At line 8, an object is eligible for garbage collection.
 
but I not sure of this answer. 
Please, Can you help me?


Doubt with notify/ notifyAll method
Tue, 6 May 2008 01:02:48 MDT
Hi,
This code is from the K&B,
 

code:
 class Reader extends Thread { 
Calculator c; 
public Reader(Calculator calc){
c = calc; 
}
public void run(){ 
synchronized(c){
try{
System.out.println("Waiting for calculation..."); 
c.wait(); 
}catch(InterruptedException e) {} 
System.out.println("Total is: " + c.total); 
} 
}
public static void main(String [] args) { 
Calculator calculator = new Calculator(); 
new Reader(calculator).start(); 
new Reader(calculator).start(); 
new Reader(calculator).start(); 
calculator.start(); 
}
}
class Calculator extends Thread { 
int ...


certification
Tue, 6 May 2008 00:44:48 MDT
i am in india. Now within 2 months i have to write scjp, whether i have to prepare for scjp 310-055 or scjp 310-065


Thread question
Mon, 5 May 2008 23:36:48 MDT
source: http://www.sun.com/training/certification/assessment/055.jsp (http://www.sun.com/training/certification/assessment/055.jsp)
[CODE
5. class Order implements Runnable {
6. public void run() {
7. try { Thread.sleep(2000); } catch (Exception e) { }
8. System.out.print("in ");
9. }
10. public static void main(String [] args) {
11. Thread t = new Thread(new Order());
12. t.start();
13. System.out.print("pre ");
14. try { t.join(); } catch (Exception e) { }
15. System.out.print("post ");
16. } } [/CODE]
 

Which two can result? (Choose two.)
 
a)in pre
b)pre in
c)in post pre
d)in pre post
e)pre in...


Scjp Logo Usage
Mon, 5 May 2008 22:44:48 MDT
Hi all
 
i have downloaded the sun logo for scjp,my query is where all can i use the logo.Can i use it in my resume?
 
Thanks
Umadas


static import and enums
Mon, 5 May 2008 11:18:47 MDT
Hi Ranchers,
I think highly of your time so if you find a minute, please, consider the following:
In case we define an enum inside a class in one package and then would like to use it in another one, what is the proper way to import it: static import or "classic" import statement since I noticed they both work and allow to use the enum name without class qualification. Similar question applies to members which are static nested classes. What do you think is correct? Appreciate your involvement.


Need Help!
Mon, 5 May 2008 11:14:47 MDT
Hi Ranchers,
 
I am having my SCJP 1.5 exam in the next week.
 
I am really tensed whether i would be able to clear the exam or not?
 
I have practiced Whilabs questions also.Is doing whizlabs helpful or not?
 
Also, there are not many mock exams for 1.5.Most of them available are for 1.4 in Javaranch FAQ.
 
I am not getting the confidence to face the exam.Someone please guide me.
 
Hoping for a positive reply.
 

Thanks,
Jaimesh.

JavaRanch Programmer Certification (SCJP)

Integer int question

Regd Multiple choice question pattern

Explaint the ouput...

Class finalization

Sylabus for SCJP 1.6

abstract interface

Chapter 6 Self Test Q1

please advice.

Question

Getting SCJP...

final objects in the enhanced loop

StackOverflowException

short and Integer

Integer.MIN_VALUE

Java Language Specification for Java 6

Serialization is not for Statics... Why??

Re take option

private constructor in abstract classes

HELP ME!

Garbage Collection

operators

Help

Coupling question

volatile keyword

15 min survey in the certification exam

Project

reg Questions for sun's scjp exam

plz help me

Inner Classes and GC

Not yet received SCJP 5 certificate from past 6 months

Object creation for Integer class

Assignments

FINAL VARIABLE DECLARATION

What happens when we print null character 'u0000' ?

Casting with Arrays that hold objects references

I didnt recieve my certification account until now!!!

Serialization

Is SCJP 1.4 still alive?

Confused...

What is the difference between null and void?

SCJP Exam

Collection.toArray() method

garbage collection?

Garbage collection question

Doubt with notify/ notifyAll method

certification

Thread question

Scjp Logo Usage

static import and enums

Need Help!