COMPUTER SCIENCE & ENGINEERING
II YEAR
PAPER – 1: OOPS & JAVA (PRACTICAL SYLLABUS)
NOTE:- The List of sample Programs are given below :{ Practice some more
related programs on each unit}
1. Familiarization with the Java compiler and Interpreter
2. Write a simple Java program to print a line of text.
3. Write a simple Java Program to Add, Subtract, Multiply and divide two
integers.
4. Write a Java program to convert the temperature from the command line in
Celsius to Fahrenheit.
5. Write a simple Java program to find if a number from the command line is
even or not.
6. Write a Java program to print numbers from 1 to n using the do … while
structure.
7. Write a Java program to print the multiplication table of a given number
n using the while structure.
8. Use break and continue statements in the above program to a)
b) skip n=5.
stop at n=8
9. Write a Java program to find the division of a student based on the marks
obtained using switch … case statements.
10. Find if a given number is prime or not using the ‘ for’ statement.
11. Write a program that prints the first 20 Fibonacci numbers.
12. Write a java program to take a word on the command line and print all
the permutations of the letters, one per line.
13. Write a program to list all the files and directories contained in a
directory given on the command line.
14. Create an array of integers and print its values, sum of values and
average of the values
15. Find the maximum value from the given array of numbers.
16. Arrange the given array into ascending order.
17. Create a string array, write values into it and print its values.
18. Write a program for addition of two matrices.
19. Create a class called distance with private data inches and feet. Add
methods to get data from user and display the user given values for an
object. Modifying access specifies to check the effect on accessing the
variables from user functions.
20. Create a class called shape with private data length and breadth. Add
methods to get data from user, display the area, perimeter and display
the user given values for an object. Create default constructor
and constructors that take one and two arguments each. Create objects to
use these constructors.
21. Create a class called test with private data x and y. Write all necessary
constructors and methods to accept data from user, display user data and
return the sum and product of these variable to the user.
22. Create a class called “complex” in Java containing data by name” r” and
“img” to represent the real and imaginary parts of a complex number.
Write all necessary constructors and destructor. Write methods that “
accept” two objects of complex class and “return” the sum , difference
and product of these two complex objects.
23. Write a class containing 3 functions by name ”area” to calculate the areas
of a square, triangle and rectangle based on whether the function by the
same name “area” is called with 1, 2 or 3 parameters.
24. A class by name “box” contains only two data members- length and breadth.
Extend it to contain another class containing a third variable called
height, write constructors for the new class, and method to calculate the
volume of the box. Implement the concept of virtual function in this
Program.
25. Write a program to create an interface by name” welcome” that contains an
unimplemented method “greeting”. Create classes called “English” and “hindi”
that implement this method to print the message “hello” and “namasthe”
respectively. Create necessary user functions to use these classes.
26. Write a class that keeps a running total of all characters passed to it (one
at a time) and throws an exception if it is passed a non-alphabetic
character.
27. Develop an applet to display a simple message “ hello”.
28. Develop an applet that contains two text fields and a button. Write program
so that the second text field displays the factorial of the number in the
first field when the button is clicked.
29. Write a java program that changes the colors of the applet when different
mouse events occur.
30. Write a java program that displays “Get” every one second, “Set” every two
second and “Go” every three seconds using three threads.
1. Familiarization with the Java compiler and Interpreter:
Remember that , before running the java program, the Java Development Kit(JDK) must be
installed properly on our system. We can refer the java text book chapter 1.12 INSTALLING AND
CONFIGURING JAVA for installation of java software on our system.
Step-1: Editing:
Enter the java program by using any standard text editor such as notepad ,ms-word or edit
in MSDOS etc., Most of the programmers prefer to use notepad.
Step-2: Saving:
While entering some lines or after completion of entering a program we can save the
Program with the class name and the extension must be java. Suppose a program
class sample
{
public static void main(String args[])
{
System.out.println("welcome to CSE students");
}
}
The above program must save with the name sample.java, and the file
Save as type must be “all files” as shown below. Sample.java is the source file.
Here location of file saving is important.
Step-3: Compiling:
After saving the program, compile the java program by using
D:\java> Javac sample.java
if there are any errors , repeat steps 1 thru 3 until program is
error free.
Step-4: Running:
If there are no errors , the javac compiler creates a file called
sample.class containing the bytecodes of the program.
Now type the command for execution as shown below
D:\java> java
sample
Now the output will be displayed as follows
welcome to CSE students
2. Write a simple Java program to print a line of text.
// prints a line of text
class sample
{
public static void main(String args[])
{
System.out.println("welcome to CSE students");
}
}
Output
welcome to CSE students
3. Write a simple Java Program to Add, Subtract, Multiply and divide two
integers.
// program to add , subtract , multiply and
// divide two integers
class ArithmeticOperations
{
public static void main(String args[])
{
int a , b ,x1,x2,x3,x4 ;
a = 10 ;
b = 6 ;
x1 = a+b;
x2 = a-b;
x3 = a*b;
x4 = a/b;
System.out.println("a = "+ a + " b= " + b);
System.out.println("a + b = "+ x1);
System.out.println("a - b = "+ x2);
System.out.println("a * b = "+ x3);
System.out.println("a / b = "+ x4);
}
}
Output
a
a
a
a
a
=
+
*
/
10 b= 6
b = 16
b = 4
b = 60
b = 1
4. Write a Java program to convert the temperature from the command line in
Celsius to Fahrenheit.
// converts temperature from celsius to fahrenheit
import java.util.*;
class CelsiusToFahrenheit
{
public static void main(String args[])
{ float c,f ;
Scanner in = new Scanner(System.in);
System.out.println("Enter temperature in Celsius");
c = in.nextInt();
f = 9*c/5 + 32;
System.out.println("Temperature in Celsius
= " + c);
System.out.println("Temperature in Fahrenheit = " + f);
}
}
input
Enter temperature in Celsius 0
output
Temperature in Celsius
= 0.0
Temperature in Fahrenheit = 32.0
input
Enter temperature in Celsius 100
output
Temperature in Celsius
= 100.0
Temperature in Fahrenheit = 212.0
input
Enter temperature in Celsius
output
34
Temperature in Celsius
= 34.0
Temperature in Fahrenheit = 93.2
input
Enter temperature in Celsius
output
-40
Temperature in Celsius
= -40.0
Temperature in Fahrenheit = -40.0
5. Write a simple Java program to find if a number from the command line is
even or not.
This java program finds if a number is odd or even. If the number is divisible by 2 then it is even,
otherwise it is odd. We use modulus operator to find remainder in our program.
// finds the
given number is either odd or even
import java.util.Scanner;
class OddOrEven
{
public static void main(String args[])
{
int x;
System.out.println("Enter an integer to check either odd or even ");
Scanner in = new Scanner(System.in);
x = in.nextInt();
if ( x % 2 == 0 )
System.out.println(x+" is an even number.");
else
System.out.println(x+" is an odd number.");
}
}
input
Enter an integer to check either odd or even 3
output
3 is an odd number.
input
Enter an integer to check either odd or even 4
output
4 is an even number.
6. Write a Java program to print numbers from 1 to n using the do … while
structure.
import java.util.Scanner;
class numbers
{ public static void main(String args[])
{ int n,i;
System.out.println("enter an integer");
Scanner in = new Scanner(System.in);
n= in.nextInt();
i=1;
do {
System.out.println(i);
i=i+1;
}
while(i<=n);
}
}
Input
enter an integer 6
output
1
2
3
4
5
6
7. Write a Java program to print the multiplication table of a given number
n using the while structure.
// prints multiplication table of n
import java.util.Scanner;
class MultiplicationTable
{
public static void main(String args[])
{
int n, i;
System.out.println("Enter an integer to print it's multiplication table");
Scanner in = new Scanner(System.in);
n = in.nextInt();
System.out.println("Multiplication table of "+n+" is :");
for ( i = 1 ; i <= 10 ; i++ )
System.out.println( n+"*"+i+" = "+(n*i));
}
}
input
Enter an integer to print it's multiplication table 5
output
Multiplication table of 5 is :
5*1 = 5
5*2 = 10
5*3 = 15
5*4 = 20
5*5 = 25
5*6 = 30
5*7 = 35
5*8 = 40
5*9 = 45
5*10 = 50
8. Use break and continue statements in the above program to a)
b) skip n=5.
stop at n=8
// prints multiplication table of n
// stop at n = 8 and skip at n = 5
import java.util.Scanner;
class MultiplicationTable1
{
public static void main(String args[])
{
int n, i;
boolean x = true;
do{
System.out.println("Enter an integer to print it's multiplication table or
8 to stop: ");
Scanner in = new Scanner(System.in);
n = in.nextInt();
if(n==8) break;
if(n==5) { System.out.println("you have entered 5 , so it is skipped");
continue;
}
System.out.println("Multiplication table of "+n+" is :");
for ( i = 1 ; i <= 10 ; i++ )
System.out.println( n+"*"+i+" = "+(n*i));
}
while(x);
System.out.println("you have entered 8 , so it is stopped");
}
}
input
Enter an integer to print it's multiplication table or 8 to stop: 4
output
Multiplication table of 4 is :
4*1 = 4
4*2 = 8
4*3 = 12
4*4 = 16
4*5 = 20
4*6 = 24
4*7 = 28
4*8 = 32
4*9 = 36
4*10 = 40
input
Enter an integer to print it's multiplication table or 8 to stop: 5
output
you have entered 5 , so it is skipped
input
Enter an integer to print it's multiplication table or 8 to stop: 7
output
Multiplication table of 7 is :
7*1 = 7
7*2 = 14
7*3 = 21
7*4 = 28
7*5 = 35
7*6 = 42
7*7 = 49
7*8 = 56
7*9 = 63
7*10 = 70
input
Enter an integer to print it's multiplication table or 8 to stop: 8
output
you have entered 8 , so it is stopped
9. Write a Java program to find the division of a student based on the marks
obtained using switch … case statements.
// program finds division.
// suppose divisions are calculated as follows
// 0..39: fail, 40..49: third class 50..59 :second class
//60..79: first class 80.. 100 : honors
//note: if we use only switch case without if statement in the
// following program, it will display honors for totmarks > 100
// and less than 109 which is meaning less because marks should not be
// out of range of 0-100.
import java.util.Scanner;
class division
{
public static void main(String Args[])
{
int totmarks;
boolean x = true;
while(x)
{
System.out.print("enter total marks between 1-100:
Scanner in = new Scanner(System.in);
totmarks = in.nextInt();
");
if (totmarks < 0 || totmarks >100)
{
System.out.println("Marks must be in between 0-100
continue;
}
switch (totmarks/10)
{
case 0:
case 1:
case 2:
case 3:System.out.println("Fail");break;
case 4:System.out.println("Third class ");break;
");
case 5:System.out.println("Second class
");break;
case 6:
case 7:System.out.println("First class
");break;
case 8:
case 9:
case 10:System.out.println("Honors");break;
}
break;
}
}
}
input
enter total marks between 1-100: 12
output
Fail
input
enter total marks between 1-100: 42
output
Third class
Input
enter total marks between 1-100: 56
output
Second class
input
enter total marks between 1-100: 65
output
First class
input
enter total marks between 1-100: 86
output
Honors
input
enter total marks between 1-100: 102
output
Marks must be in between 0-100
enter total marks between 1-100: 98
Honours
input
enter total marks between 1-100: 105
output
Marks must be in between 0-100
enter total marks between 1-100: 52
Second class
9b)ans
import java.io.*;
public class Grader
{
public static void main(String args[]) throws Exception
{
BufferedReader b=new BufferedReader(new InputStreamReader(System.in));
System.out.println("please select the range of your marks to know your
Division \n1.>70% \n2.60-70% \n3.<60%");
int ch=Integer.parseInt(b.readLine());
switch(ch)
{
case 1: System.out.println("Your have passed the exam in Division:First class
with Distinction");
break;
case 2: System.out.println("Your have passed the exam in Division:First
class");
break;
case 3: System.out.println("Your have passed the exam in Division:Second
Class");
break;
}
}
}
input
please select the range of your marks to know your Division 1
1.>70%
2.60-70%
3.<60%
output
Your have passed the exam in Division:First class with Distinction
input
please select the range of your marks to know your Division 3
1.>70%
2.60-70%
3.<60%
output
Your have passed the exam in Division:Second Class
input
please select the range of your marks to know your Division 2
1.>70%
2.60-70%
3.<60%
output
Your have passed the exam in Division:First class
10. Find if a given number is prime or not using the ‘ for’ statement.
//
//
//
//
//
Prime number: A number which is only divisible by one and itself is called a
prime number. Divisible means remainder is zero. 7 is a prime number because
it is only divisible by one and seven. 8 is not a prime number because it is
divisible by one, two, four and eight.
program finds a number is prime or not
import java.util.Scanner;
class PrimeNumber {
public static void main(String args[])
{
int n, j ,status = 1 ;
Scanner in = new Scanner(System.in);
System.out.println("Enter a number to find whether prime or not");
n = in.nextInt();
for ( j = 2 ; j <= Math.sqrt(n) ; j++ )
{
if ( n % j == 0 )
{
status = 0;
System.out.println(n+" is not a prime number");
break;
}
}
if ( status == 1 )
{
System.out.println(n+" is a prime number ");
}
}
}
input
Enter a number to find whether prime or not 7
output
7 is a prime number
input
Enter a number to find whether prime or not 8
output
8
is not a prime number
11. Write a program that prints the first 20 Fibonacci numbers.
// First few numbers of Fibonacci series are 0, 1, 1, 2, 3, 5, 8 ,etc
// Except first two terms in sequence every other term is the sum of two previous
//terms, For example 8 = 3 + 5 (addition of 3, 5). This sequence has many applications
//in mathematics and Computer Science.
// prints first 20 Fibonacci numbers
class Fibonacci
{
public static void main(String args[])
{
int f1, f2, f3, c;
f1 = 0;
f2 = 1 ;
System.out.println("First 20 Fibonacci numbers:");
for(c=1;c<=20;c++)
{
System.out.println(f1);
f3=f1+f2;
f1=f2;
f2=f3;
}
}
}
output
First 20 Fibonacci numbers:
0
1
1
2
3
5
8
13
21
34
55
89
144
233
377
610
987
1597
2584
4181
12. Write a java program to take a word on the command line and print all
the permutations of the letters, one per line.
import java.util.*;
public class PermutationExample
{
public static void main(String args[]) throws Exception
{
Scanner input = new Scanner(System.in);
System.out.print("Enter String: ");
String chars = input.next();
showPattern("", chars);
}
public static void showPattern(String st, String chars) {
if (chars.length() <= 1)
System.out.println(st + chars);
else
for (int i = 0; i < chars.length(); i++) {
try {
String newString = chars.substring(0, i)
+ chars.substring(i + 1);
showPattern(st + chars.charAt(i),
newString);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
input
Enter String: abc
Output
abc
acb
bac
bca
cab
cba
input
Enter String: xy
output
xy
yx
13. Write a program to list all the files and directories contained in a
directory given on the command line.
//lists all files in a directory
import java.io.File;
public class ListFiles
{
public static void main(String[] args)
{
// Directory path here
// example of input D:\\java
String path = "."; //default current directory when it is .(dot)
String files;
File folder = new File(path);
File[] listOfFiles = folder.listFiles();
for (int i = 0; i < listOfFiles.length; i++)
{
if (listOfFiles[i].isFile())
{
files = listOfFiles[i].getName();
System.out.println(files);
}
}
}
}
output
3.java
4.doc
5.doc
5.java
6.doc
6.java
7.doc
8.doc
9.doc
A.class
AddNumbers.class
AddNumbers.java
AddTwoMatrix.class
AddTwoMatrix.doc
AddTwoMatrix.java
AEvent.class
14. Create an array of integers and print its values, sum of values and
average of the values.
// creates an array of integers and print its values, sum of values and
// average of the values
import java.util.Scanner;
class ArrayExample{
public static void main(String args[]){
int i,n,s=0,a[] ;
float average;
System.out.println("How many values in an array");
Scanner in = new Scanner(System.in);
n = in.nextInt();
a = new int[n];
System.out.println("enter"+n+"values line by line");
for(i=0;i<n;++i){
System.out.print("enter a value");
a[i] = in.nextInt();
s+=a[i];}
average = (float)s/n ;
System.out.println("Given Array");
for(i=0;i<n;++i){
System.out.println(a[i]);}
System.out.println("sum="+s);
System.out.println("Average="+average);
} }
input
How many values in an array 5
Enter 5 values line by line
enter a value 12
enter a value 3
enter a value 24
enter a value 32
enter a value 5
output
Given Array
12
3
24
32
5
sum=76
Average=15.2
15. Find the maximum value from the given array of numbers.
// finds maximum value in a given array of integers
import java.util.Scanner;
class ArrayMax{
public static void main(String args[]){
int i,n,max,a[] ;
System.out.println("How many values in an array");
Scanner in = new Scanner(System.in);
n = in.nextInt();
a = new int[n];
System.out.println("enter "+n+" values line by line");
for(i=0;i<n;++i){
System.out.print("enter a value: ");
a[i] = in.nextInt();}
//process to find maximum value
max = a[0];
for(i=1;i<n;++i){
if(max < a[i]) max = a[i]; }
System.out.println("Given Array");
for(i=0;i<n;++i){
System.out.println(a[i]);}
System.out.println("Maximum value = "+max);
}
}
input
How many values in an array 5
enter 5 values line by line
enter a value: 12
enter a value: 23
enter a value: 45
enter a value: 32
enter a value: 18
output
Given Array
12
23
45
32
18
Maximum value = 45
16. Arrange the given array into ascending order.
// Sorting an Array of integers
import java.util.*;
class ArraySort{
public static void main(String args[]){
int i,n,a[] ;
System.out.print("How many values in an array:
Scanner in = new Scanner(System.in);
n = in.nextInt();
");
a = new int[n]; //specifies array size
System.out.println("enter "+n+" values line by line");
for(i=0;i<n;++i){
System.out.print("enter a value: ");
a[i] = in.nextInt();}
System.out.println("Given Array");
for(i=0;i<n;++i){
System.out.println(a[i]);}
// for array sorting
Arrays.sort(a);
System.out.println("Sorted Array in ascending order");
for(i=0;i<n;++i){
System.out.println(a[i]);}
}
}
input
How many values in an array: 5
enter 5 values line by line
enter a value: 24
enter a value: 13
enter a value: 6
enter a value: 43
enter a value: 11
output
Given Array
24
13
6
43
11
Sorted Array in ascending order
6
11
13
24
43
17. Create a string array, write values into it and print its values.
// Array with strings
import java.util.*;
class ArrayString{
public static void main(String args[]){
int i,n;
String[] a = new String[]{"Govardhan","Bheemeswar","Ramarao",
"Rajareddy", "Basavraj"};
n = a.length;
for(i=0;i<n;++i){
System.out.println(a[i]);}
}
}
Output
Govardhan
Bheemeswar
Ramarao
Rajareddy
Basavraj
18. Write a program for addition of two matrices.
// Matrix Addition
import java.util.Scanner;
class MatrixAddition
{
public static void main(String args[])
{
int m,n,c,d;
Scanner in = new Scanner(System.in);
System.out.println("Enter the number of rows and columns of a matrix)");
m = in.nextInt();
n = in.nextInt();
int first[][] = new int[m][n];
int second[][] = new int[m][n];
int sum[][] = new int[m][n];
System.out.println("Enter "+m*n+" elements of first matrix");
for ( c = 0 ; c < m ; c++ )
for ( d = 0 ; d < n ; d++ )
first[c][d] = in.nextInt();
System.out.println("Enter "+m*n+" elements of second matrix");
for ( c = 0 ; c < m ; c++ )
for ( d = 0 ; d < n ; d++ )
second[c][d] = in.nextInt();
// process of addition
for ( c = 0 ; c < m ; c++ )
for ( d = 0 ; d < n ; d++ )
sum[c][d] = first[c][d] + second[c][d];
// printing first matrix
System.out.println("First Matrix is:-");
for ( c = 0 ; c < m ; c++ )
{
for ( d = 0 ; d < n ; d++ )
System.out.print(first[c][d]+"\t");
System.out.println();
}
// printing second matrix
System.out.println("Second Matrix is:-");
for ( c = 0 ; c < m ; c++ )
{
for ( d = 0 ; d < n ; d++ )
System.out.print(second[c][d]+"\t");
System.out.println();
}
System.out.println("Sum of entered matrices:-");
for ( c = 0 ; c < m ; c++ )
{
for ( d = 0 ; d < n ; d++ )
System.out.print(sum[c][d]+"\t");
System.out.println();
}
}
}
input
Enter the number of rows and columns of a matrix
2
2
Enter 4 elements of first matrix
1
2
3
4
Enter 4 elements of second matrix
5
6
7
8
output
First Matrix is:1
2
3
4
Second Matrix is:5
6
7
8
Sum of entered matrices:6
8
10
12
19. Create a class called distance with private data inches and feet. Add
methods to get data from user and display the user given values for an
object. Modifying access specifies to check the effect on accessing the
variables from user functions.
public class Distance
{
private int inches;
private int feet;
public int getInches()
{
return inches;
}
public void setInches(int inch)
{
inches = inch;
}
public int getFeet()
{
return feet;
}
public void setFeet(int f)
{
feet = f;
}
public static void main(String args[])
{
Distance distance = new Distance();
//setting the values
distance.setInches(10);
distance.setFeet(20);
//displaying the values
System.out.println("inches= "+distance.getInches());
System.out.println("feet
"+distance.getFeet());
}
}
output
inches= 10
feet
20
20. Create a class called shape with private data length and breadth. Add
methods to get data from user, display the area, perimeter and display
the user given values for an object. Create default constructor
and constructors that take one and two arguments each. Create objects to
use these constructors.
//finds Area and Perimeter of a Rectangle
import java.util.Scanner;
class Rectangle
{
int length;
int breadth;
Rectangle(int x,int y)
{
length=x;
breadth=y;
}
int rectArea()
{
return(length*breadth);
}
int rectPerimeter()
{
return(2*(length+breadth));
}
}
class Shape
{
public static void main(String args[])
{
int p , q ;
System.out.print("Enter length: ");
Scanner in = new Scanner(System.in);
p = in.nextInt();
System.out.print("Enter breadth: ");
q = in.nextInt();
Rectangle rect1=new Rectangle(p,q);
int area1=rect1.rectArea();
int perimeter1 = rect1.rectPerimeter();
System.out.println("Length ="+p);
System.out.println("Breadth="+q);
System.out.println("Area of a Rectangle ="+area1);
System.out.println("Perimeter of a Rectangle ="+perimeter1);
}
}
input
Enter length: 5
Enter breadth:6
output
Length =5
Breadth=6
Area of a Rectangle =30
Perimeter of a Rectangle =22
21. Create a class called test with private data x and y. Write all necessary
constructors and methods to accept data from user, display user data and
return the sum and product of these variable to the user.
//accepts user data for x and y and displays user data , sum and product
// of those variables by using methods
import java.util.Scanner;
public class Test{
/** Main method */
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("Enter first value: ");
int i = in.nextInt();
System.out.print("Enter second value: ");
int j = in.nextInt();
int k = sum(i, j);
int l = product(i,j);
System.out.println("First value = "+i);
System.out.println("Second value = "+j);
System.out.println("The
" and " +
System.out.println("The
" and " +
sum of " +
j + " is "
product of
j + " is "
i
+
"
+
+
k);
+ i +
l);
}
/** Return the sum of two numbers */
private static int sum(int x, int y) {
int result;
result = x + y;
return result;
}
/** Return the product of two numbers */
private static int product(int x, int y) {
int result;
result = x * y;
return result;
}
}
input
Enter first value: 5
Enter second value: 3
output
First value = 5
Second value = 3
The sum of 5 and 3 is 8
The product of 5 and 3 is 15
22. Create a class called “complex” in Java containing data by name” r” and
“img” to represent the real and imaginary parts of a complex number.
Write all necessary constructors and destructor. Write methods that “
accept” two objects of complex class and “return” the sum , difference
and product of these two complex objects.
// complex number operations addition,
// subtraction and multiplication
import java.util.Scanner;
class Complex1
{
public double realno;
public double imgno;
Complex1(){
}
Complex1(double r,double i)
{
realno=r;
imgno=i;
}
public Complex1 add(Complex1 x, Complex1 y)
{
double r = x.realno + y.realno;
double i = x.imgno + y.imgno;
return
}
public
{
double
double
return
}
public
{
double
double
return
}
new Complex1(r,i);
Complex1 subtract(Complex1 x, Complex1 y)
r = x.realno - y.realno;
i = x.imgno - y.imgno;
new Complex1(r,i);
Complex1 multiply (Complex1 x, Complex1 y)
r2 = x.realno * y.realno - x.imgno * y.imgno;
i2 = x.imgno * y.realno + x.realno * y.imgno;
new Complex1 (r2, i2);
public String toString ()
{
String imgsign = (imgno < 0) ? " - " : " + ";
if (imgno < 0) imgno = -imgno ;
return ("("+realno+") " + imgsign + "("+imgno + "i)");
}
}
class TestComplex
{
public static void main (String args[])
{
String x = "+";//used x to print complex number as it is such as 2+3i
double xr,xi,yr,yi; //two complex numbers are xr+xi & yr+yi
//using instance methods
Scanner in = new Scanner(System.in);
System.out.println("Enter first real no");
xr = in.nextDouble();
System.out.println("Enter first imaginary no");
xi = in.nextDouble();
System.out.println("Enter Second real no");
yr = in.nextDouble();
System.out.println("Enter Second imaginary no");
yi = in.nextDouble();
Complex1 a = new Complex1 (xr,xi);// example first expression (2+3i)
Complex1 b = new Complex1 (yr,yi);// example second expression (4+6i)
Complex1 complex1 = new Complex1();
Complex1 value1 = complex1.add(a,b);
Complex1 value2 = complex1.subtract (a,b);
Complex1 value3 = complex1.multiply (a,b);
System.out.println("Following result is using instance methods: ");
System.out.println("first complex number :"+a.realno + x + a.imgno +"i");
System.out.println("Second complex number :"+b.realno + x + b.imgno +"i");
System.out.println("Addition : "+value1);
System.out.println("Subtraction : "+value2);
System.out.println("Multiplication : "+value3);
}}
input
Enter first real no 2
Enter first imaginary no 3
Enter Second real no 4
Enter Second imaginary no 5
output
Following result is using instance methods:
first complex number :2.0+3.0i
Second complex number :4.0+5.0i
Addition : (6.0) + (8.0i)
Subtraction : (-2.0) - (2.0i)
Multiplication : (-7.0) + (22.0i)
input
Enter first real no 4
Enter first imaginary no 6
Enter Second real no -2
Enter Second imaginary no -5
output
Following result is using instance methods:
first complex number :4.0+6.0i
Second complex number :-2.0+-5.0i
Addition : (2.0) + (1.0i)
Subtraction : (6.0) + (11.0i)
Multiplication : (22.0) - (32.0i)
23. Write a class containing 3 functions by name ”area” to calculate the areas
of a square, triangle and rectangle based on whether the function by the
same name “area” is called with 1, 2 or 3 parameters.
//calculate the areas of a square, triangle and rectangle based
// on whether the function by the same name “area” is
// called with 1, 2 or 3 parameters.
// here we used BufferReader and Integer.ParseInt instead of Scanner in for
inputting values
import java.io.*;
class areas
{
void area(int a )
{
System.out.println( "\n Area of a square with side
}
"+a+" is :" + a*a);
void area(int a, int b, int c)
{
double temp = (a + b + c);
double s= temp/2;
double triarea = Math.sqrt(s*(s-a)*(s-b)*(s-c));
System.out.println( "\n Area of triangle with lenght of sides "+a+","
+b+ " and " +c+" is : "+ triarea);
}
void area(int a , int b)
{
System.out.println( "\n Area of a Rectangle of length " +a+ " and
breadth "+b+ " is :" + a * b);
}
public static void main(String args[]) throws IOException
{
areas d = new areas();
BufferedReader Br = new BufferedReader(new InputStreamReader(System.in));
System.out.print("\n Find area of \n 1 . Square \n 2 . Triangle \n 3 . Rectangle
\n\nSelect a choice : ");
int choice =Integer.parseInt(Br.readLine());
switch(choice)
{
case 1:
System.out.print("\n Enter the side : ");
int a =Integer.parseInt(Br.readLine());
d.area(a);
break;
case 2:
System.out.print("\n Enter the lenght of first side : ");
int x =Integer.parseInt(Br.readLine());
System.out.print("\n Enter the lenght of second side : ");
int y=Integer.parseInt(Br.readLine());
System.out.print("\n Enter the lenght of third side : ");
int z =Integer.parseInt(Br.readLine());
d.area(x,y,z);
break;
case 3:
System.out.print("\n Enter the length : ");
int l =Integer.parseInt(Br.readLine());
System.out.print("\n Enter the breadth : ");
int b =Integer.parseInt(Br.readLine());
d.area(l,b);
break;
default:
System.out.println("Invalid choice");
}
}
}
output
Find area of
1 . Square
2 . Triangle
3 . Rectangle
Select a choice : 1
Enter the side : 3
Area of a square with side
3 is :9
Find area of
1 . Square
2 . Triangle
3 . Rectangle
Select a choice :
Enter the lenght
Enter the lenght
Enter the lenght
Area of triangle
Find area of
1 . Square
2 . Triangle
2
of first side : 2
of second side : 3
of third side : 4
with lenght of sides
2,3 and 4 is : 2.9047375096555625
3 . Rectangle
Select a choice : 3
Enter the length : 6
Enter the breadth : 5
Area of a Rectangle of length 6 and breadth 5 is :30
Find area of
1 . Square
2 . Triangle
3 . Rectangle
Select a choice : 5
Invalid choice
24. A class by name “box” contains only two data members- length and breadth.
Extend it to contain another class containing a third variable called
height, write constructors for the new class, and method to calculate the
volume of the box. Implement the concept of virtual function in this
Program.
//a class Box contains length and breadth
//and another BoxVolume contains length,breadth and height
// here we used virtual function
class Box {
int length , breadth;
Box(int x, int y){
length = x;
breadth = y;}
int area(){
return(length*breadth);}}
class BoxVolume extends Box {
int height;
BoxVolume(int x, int y, int z){
super(x,y);
height = z;}
int volume(){
return(length*breadth*height);}}
class Box1 {
public static void main(String arg[]){
BoxVolume volume1= new BoxVolume(10,15,5);
int p = volume1.area();
int q = volume1.volume();
System.out.println("area = " + p);
System.out.println("volume= " + q);
}}
output
area = 150
volume= 750
25. Write a program to create an interface by name” welcome” that contains an
unimplemented method “greeting”. Create classes called “English” and “hindi”
that implement this method to print the message “hello” and “namasthe”
respectively. Create necessary user functions to use these classes.
Ans
interface Welcome
{
String greeting();
}
class English implements Welcome
{
public String greeting()
{
return "Hello";
}
}
class Hindi implements Welcome
{
public String greeting()
{
return "Namaste";
}
}
public class Test
{
public static void main(String ar[])
{
English eng=new English();
Hindi hin = new Hindi();
System.out.println("Greetings in English: "+eng.greeting());
System.out.println("Greetings in Hindi: "+hin.greeting());
}
}
26. Write a class that keeps a running total of all characters passed to it (one
at a time) and throws an exception if it is passed a non-alphabetic
character.
Ans)
import java.io.*;
class Checker
{
boolean check(String s)
{
boolean hasNonAlpha = s.matches("^.*[^a-zA-Z].*$");
return hasNonAlpha;
}
public static void main(String ar[]) throws Exception
{
Checker ch=new Checker();
BufferedReader b=new BufferedReader(new InputStreamReader(System.in));
while(true)
{
String s=b.readLine();
if(ch.check(s)!=true)
{
}
else
{
System.exit(0);
}
}
}
}
27. Develop an applet to display a simple message “ hello”.
//develop an Applet to display a simple message “hello”
Her we are giving step wise procedure to create and run an applet
First create a java program hellojava.java
import java.awt.*;
import java.applet.*;
public class hellojava extends Applet
{public void paint (Graphics g)
{
g.drawString("hello",10,100);
}}
When this above program is error free , automatically it creates hellojava.class and then create an html
tag hellojava.html as follows. The <applet> tag is the basis for embedding an applet in an HTML file.
Below is an example that invokes an applet:
<HTML>
<BODY>
<APPLET CODE= hellojava.class
WIDTH=400
HEIGHT=200>
</APPLET>
</BODY>
</HTML>
An applet may be invoked by embedding directives in an HTML file and viewing the file through an
applet viewer or Java-enabled browser.
If we use appletviewer
appletviewer hellojava.html causes to display as follows.
28. Develop an applet that contains two text fields and a button. Write program
so that the second text field displays the factorial of the number in the
first field when the button is clicked.
// Develop an applet that contains two text fields and a button. Write program
//
so that the second text field displays the factorial of the number in the
//
first field when the button is clicked.
import java.awt.*;
import java.awt.event.*;
public class FactEvent extends java.applet.Applet implements ActionListener
{
TextField t1,t2;
int fact=1,m;
Button b1,b2,b3;
String msg;
Label l1,l2;
FactEvent e;
public void init()
{
e=this;
t1=new TextField(3);
t2=new TextField(10);
b1=new Button("FIND FACTORIAL");
l1=new Label("ENTER THE NUMBER");
l2=new Label("RESULT");
add(l1);
add(t1);
add(l2);
add(t2);
add(b1);
b1.addActionListener(this);
}
public void actionPerformed(ActionEvent ae)
{
String str=t1.getText();
if(str!="")
{
int num=Integer.parseInt(str);
for(int i=num;i>0;i--)
{
fact=fact*i;
}
msg="" +fact;
t2.setText(msg);
fact=1;
}
}
}
When the above FactEvent.java is error free , it will create FactEvent.class.
Now create FactEvent.html as shown below
<HTML>
<BODY>
<APPLET CODE= FactEvent.class
WIDTH=400
HEIGHT=200>
</APPLET>
</BODY>
</HTML>
To see the results, run the applet as follows
appletviewer FactEvent.html
then result will be as follows
29. Write a java program that changes the colors of the applet when different
mouse events occur.
//changes the colors of the applet when different mouse event occurs
import java.applet.Applet;
import java.awt.*;
public class ColorButtons extends Applet {
Button red, green, blue, reset;
Color bgColor;
public void init() {
// specify the buttons
red = new Button();
red.setBackground(Color.red);
green = new Button();
green.setBackground(Color.green);
blue = new Button();
blue.setBackground(Color.blue);
reset = new Button("Reset");
// find the default color and choose this for reset button
bgColor = getBackground();
reset.setBackground(bgColor);
// add the buttons to the applet
add(red);
add(green);
add(blue);
add(reset);
}
public boolean action(Event evt, Object arg) {
// if one of the buttons is pressed, change the background color
if (evt.target == red)
setBackground(Color.red);
else if (evt.target == green) setBackground(Color.green);
else if (evt.target == blue) setBackground(Color.blue);
else if (evt.target == reset) setBackground(bgColor);
// recolor the buttons
red.setBackground(Color.red);
green.setBackground(Color.green);
blue.setBackground(Color.blue);
reset.setBackground(bgColor);
// repaint the applet
repaint();
return true;
}
}
Now create ColorButtons.html file as follows
<HTML>
<HEAD>
</HEAD>
<BODY>
<APPLET CODE="ColorButtons.class" WIDTH="800" HEIGHT="500"></APPLET>
</BODY>
</HTML>
29b)ans
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class MouseEvent1 extends Applet implements MouseListener{
public void init() {
this.addMouseListener(this);
}
public void mouseClicked(MouseEvent e){
setBackground(Color.blue);
}
public void mouseEntered(MouseEvent e){
setBackground(Color.cyan);
}
public void mouseExited(MouseEvent e){
setBackground(Color.green);
}
public void mousePressed(MouseEvent e){
setBackground(Color.magenta);
}
public void mouseReleased(MouseEvent e){
setBackground(Color.yellow);
}
}
MouseEvent1.html will be created as follows
<HTML>
<HEAD>
</HEAD>
<BODY>
<APPLET ALIGN="CENTER" CODE="MouseEvent1.class" WIDTH="800"
HEIGHT="500"></APPLET>
</BODY>
</HTML>
When we run the applet as given below
Appletviewer MouseEvent1.html
Applet background will changes with different colors for different mouse events.
30. Write a java program that displays “Get” every one second, “Set” every two
second and “Go” every three seconds using three threads.
class A extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(1000);
System.out.println("get");
}
}
catch(Exception e)
{}
}
}
class B extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(2000);
System.out.println("Set");
}
}
catch(Exception e)
{}
}
}
class C extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(3000);
System.out.println("Go");
}
}
catch(Exception e)
{}
}
}
class ThreadDemo
{
public static void main(String args[])
{
A t1=new A();
B t2=new B();
C t3=new C();
t1.start();
t2.start();
t3.start();
}
}