MCA (Revised)Term-End Examination

December, 2OO8

MCS-024 : OBJEGT ORIENTEDTECHNOLOGIES AND JAVA

PROGRAMMING

Time : 3 hours Maximum Marks : 1.04

Nofe : Question number 7 is compulsory. Attemptany three questions from the rest.

1. (a)

(b)

(c)

What is the difference between Polymorphismand Encapsulation ? 4

Write a program that displays a diamond usingasterisks (*) as follows : 6

***

** **

:N. *

YName three threads that are createdautomatically by the Java virtual machine anddiscuss the purpose of each thread. 4

MCS-024 P.T .O .

Explain the following and their usage usingsuitable examples :(i) Extends(ii) Implements(iiO Final

Find the errors in the following Java programsand correct them :

(i) int go{

system.out.println ("lnside method g");int ho

{system.out.println ("lnside method h");

l(iil int sum (int x,. int y)

tint result;result = x*V;

l

What is a package in Java and what are theaccess criteria ? Fxplain with suitable examples.

MCS-O24

What is explicit casting ? Explain with suitableexample.

What is the difference between declaring avariable and defining a variable ? Explain withthe help of example.

2. (a) What is the dillerence between the booleanoperator & and the && operator ? Explainwith suitable example.

(b) Find the errors in the following Java program,and correct them :

Class Examination;

{public void main (argsl]){system.out.println ("java is an OOL")

int i = 10;f o r ( i > 0 ; i - - )system.out.println ("i =

II

)(c) Write a program to implement Quick Sort

technique.

MCS-024 3 P.

k)

(d) Find and correct the error in each of thefollowing segments : 4

(i) final int A-size = 5;A_size = 10;

(ii) Assumeint a[ ] [ ] : {{1, 2}, {3, 4}},a[1', 1] = $t

3. (a) Write a Java applet to show a sine wave with.

variable frequency on a web page. 6

(b) What do you mean by "this" keyword ?Explain with example.,

(c) What is an event ? Explain differentcomponents of an event.

(d) What gives Java it's "write once and runanywhere" nature ?

4. (a) What is multithreading ? Explain twoadvantages of multithreaded programs. Write aprogram in Java to explain how differentpriorities can be assigned to different threads.

What is a servlet ? Explain the use of GET andPOST methods.

What is the use of 'synchronize' keyword ?

1 0

4

3

(b)

(c)

MCS-O24

(d) What is a datagram socket ? Explain the use ofdatagram socket through an example of aprogram written in Java. 3

Compare and contrast break .and continue

staternent. 3

What happens when a return lype, even,void isspecified fgr a constructor ? What do youunderstand by parameterized constructors ?

5. (a)

(b)

Explain with one example.(c) Find the errors in the following Java program

and correct them :( i ) ! = 1 ;

while ( i .= 10);i++; l

( i i ) for (k : 0.1; k! = 1.0; k += 0.1)System.out.println (k);

(d) Write a program that calculates the product ofthe odd integers from 1 to 15.

(e) Compare and contrast Java Beans and JavaServlets.

MCS-024 1 1 ,000