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In the first round, there are 30 aptitude and 30 java
questions. We are suppose to finish both the papers within
60 minutes.

I cleared this round.

Next was test for programming skills.
In this section, Some 7 n's were asked.

What is the difference b/w sleep(1000) and wait(1000)
what is the diff b/w static block and static function?
Write a program to validate IP address using string
Write a program to create singleton class
write a function to reverse the string
Write a prog to print prime nos upto n. EX: If n=9, It shld
print 1,2,3,5,7
7. One program on collections- Write a program to print no.
of times a number is repeating in an array.
EX- {1,3,1,2,5,7,3,7,34,3,8,3}
It should print: 1- 2 times
3- 4 times and so on

7. Write a func to print fibonocci series

After this I had technical interview, which went on for.
60 mins or so. There were qn's about multi threading,
Exception handling and collection classes.

Knowledge about collections was very important for the
post I was interviewed for.

In the first round, there are 30 aptitude and 30 java questions. We are suppose to finish both the..

Answer / koundinya_1993

1 ans)
Wait() : This function takes parameters as milliseconds and
puts the thread in wait state for the desired time of the
programmer after time passes the execution starts again.

Sleep() : This function is also used for same purpose using
his function by java you can put a thread in sleep
state .sleep does not contains any parameters so the thread
will not be automatically start execution It needs a wake
up signal again which can be Notify().or other function are
also provided by java.

So the main difference in Wait() and sleep() is wait takes
time parameter and wait for specific time only and sleep
throws a thread in sleep mode for unspecified time.

2)Static Block is executed when the Program starts.

Example :

public class StaticExample {


public static void main(String args[]){


When we run this program it will print Hello.

Static Methods are executed when those methods are called
from another static class or method

Example :

public class StaticExample {

static void printString(){

static void testStaticMethod(){

public static void main(String args[]){

4) singleton class:

A singleton class is one which is having a single object.It
is mainly used for the management purpose such as database

public class SingletonPattern{
private static SingletonPattern instance;
private SingletonPattern(){}
public static synchronized SingletonPattern getInstance(){
if (instance == null)
instance = new SingletonPattern();
return instance;
public static void main(String arg[]){
System.out.println("The output of two instance:");
SingletonPattern sp=new SingletonPattern();
System.out.println("First Instance: "+sp.getInstance());
sp=new SingletonPattern();
System.out.println("Second Instance:"+sp.getInstance());

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