Computer Applications Model Paper

Try Solving These Questions

More Coming Soon !!

Q7 .(a) Write a program to input the number of a week and print the corresponding day. Assume 1 for Monday, 7 for Sunday, etc. also give the proper message for the wrong number input.

(b). Write a program to enter the name and convert its each lower case letters to uppercase and vice versa.

Example : Input - Subhash Chandra Bose

Output- sUBHASH cHANDRA bOSE

Q8. Write a program to input a sentence. Create a function convert(int n), where n is an integer value in positive or negative. This function is used to encode or decode the given string by shifting each character of a string the number of times as specified by user.

Ex.- Input- Good Boy

Shift value –3

Output – Jrrg Erb

You can see that this function does not affect the spaces. Also if it reaches end of the alphabet list it starts the list again.(see the state of ‘y’ in “Boy” above, it changes to ‘b’). in the similar manner if the entered shift value of n is in negative then all the characters in a string will shift backwards.

Q9. The distance between two cities is measured in Kilometers(km) and Meters(m). Thus to add distance of two cities from the current city we need to add its km and m of one city with the km and m of other city. You must remember that 1000 meters makes one(1) Kilometer. Write a class with the following data members to add the distance of two cities from the current city.:

Class name : distance

Data members

Integer : km ,m

Methods

Distance Run(distance,distance) : to input two distances and to add them into the third

Display : to display the total distance.

Display the constructor required to initialize the objects.

Q10. Write a program to create a double dimensional array[4*4] to store 16 elements and to perform the following operations as per user choice-

1. To print the position of largest and least element

2. To print the sum of its diagonal elements

3. To print the sum of all the elements.

Q11. Design a class named “Database”. It has name, address, city, pin code and basic salary as data members. it also has member functions to input data, print data and calculate Dearness allowance which is 150% of basic salary, House rent which is 40% of basic salary and gross salary which is sum of basic, D.A. and H.R.A. A parameterized constructor is used to pass initial values to arguments by implicit call method.

Define the class “ Database”. Also create an object of the class.

Q12. Write a program to initialize an array of 5 names and initialize another array with their respective telephone numbers. Search for a name input by the user, in the list. If found, display “Search Successful” and print the name along with the telephone number, otherwise display “Search unsuccessful. Name not listed”.

Program To Print All the NON Fibonacci Numbers

Write a function print() that accepts two numbers and print all the numbers between them,except those two numbers
Using this function, write a program to print all the non-fibonacci numbers from 1-100

Quadratic Equation

Wap to input the values of three coefficients of a quadratic equation
AX(Square)+BX+C=0
Find the roots of the Equation and display them , stating wether they are real,imaginary or equal
Also print the value of X

import java.io.*;
class Quadratic
{
public int a,b,c;
public void Quadratic()throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter the value A");
int a = Integer.parseInt(br.readLine());
System.out.println(" Enter the value B ");
int b = Integer.parseInt(br.readLine());
System.out.println(" Enter the value C ");
int c = Integer.parseInt(br.readLine());
}
public void Values()
{
double x1,x2;
int z = (b*b)-(4*a*c);
if(z>0)
{
System.out.println(" Real Roots ");
x1=(-b+Math.sqrt(b*b-4*a*c))/(2*a);
System.out.println( " Root 1 " + x1);
x2=(-b-Math.sqrt(b*b-4*a*c))/(2*a);
System.out.println( " Root 2 " + x2);
}
else if(z==0)
{
System.out.println(" Equal Roots ");
x1= (b)/(2*a);
System.out.println(" Root = " +x1);
}
else if(z<0)
{
System.out.println(" Imaginary Roots ");
}
}
public static void main(String args[])throws IOException
{
Quadratic Q = new Quadratic();
Q.Quadratic();
Q.Values();
}
}

String based Program

Write a Program to accept a String and print it in following manner
Input - Harsh Kumar Agrawal ( Just an Example)
Output - H.K.Agrawal

Frequency Of Vowels In the String

Q Write a Program to Find the Number of times vowels Occure in a given String

Method 1 - Of anshul
import java.io.*;
class vowels{ public static void main()throws IOException
{
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
String str;
int i,c=0,j;
System.out.println("Enter a string");
str=in.readLine();
str=str.toLowerCase();
for(i=0;i<=str.length()-1;i++)
{
j=str.charAt(i);
if(j==' ')
{
if((j+1)=='a'(j+1)=='e'(j+1)=='i'(j+1)=='o'(j+1)=='u')
c++;
}
}
if(str.charAt(0)=='a'str.charAt(0)=='e'str.charAt(0)=='i'str.charAt(0)=='o'str.charAt(0)=='u')
c++;
System.out.println("\n no. of words starting with vowels::::"+c);
}
}

Method 2 (By Harsh)(me :))
import java.io.*;
class Proverbial
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter a String ");
String s=br.readLine();
char ch;
s=s.toLowerCase();
int c=0,l=s.length();
for(int i=0;i
{
ch=s.charAt(i);
if(ch=='a'||ch=='e'||ch=='i'||ch=='o'||ch=='u')
c++;
}
System.out.println(" Frequency of Vowels is "+ c);
}
}

Perfect Number

A perfect Integer is a number which is equal to the sum of all its factors
eg - 28 is a perfect integer as it is the sum of all its factor -
1 + 2 + 4 + 7 + 14 = 28
Wap to display perfeect integers form 1 to 1000
Evergreen Publications Model Paper1 Q9

[2D Array] Sum of diagonals

Wap To input numbers into a array of 3 rows And 3 coloumns . find the sum of the numbers in the diagonal elements . no element should be repeated twice
Evergreen Publication Model paper 1 Q8

import java.io.*;
class SumDiagonal
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a[][]=new int[3][3];
int Sum=0;
System.out.println(" Enter 6 elements for array one :");
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
a[i][j]=Integer.parseInt(br.readLine());
}
}
System.out.println(" Matrix ");
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
System.out.print(a[i][j]+"\t");
}
System.out.println();
}
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
if(i==j)
Sum = Sum + a[i][j];
if(i+j==2&&i!=j)
Sum = Sum + a[i][j];
}
}
System.out.println("Sum of Diagonal = "+Sum);
}
}

Request a Program Here

Here u can Ask a question for a Program and i'll make that program and publish it here

HCF and LCM of 2 numbers

import java.io.*;
class lowhigh
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a,b,c,i,j,t,k,p,lcm,hcf=1;
System.out.println(" Enter any 3 number ");
a = Integer.parseInt(br.readLine());
b = Integer.parseInt(br.readLine());
c = Integer.parseInt(br.readLine());
p = a*b*c;
for(i=1;i<=p;i++)
{
j = a%i;
t = b%i;
k = c%i;
if(j==0&&t==0&&k==0)
{
hcf = i;
}
}
lcm = p/hcf;
System.out.println(" the lcm is " + lcm);
System.out.println(" the hcf is " + hcf);
}
}

Find the Longest Word in the String

import java.io.*;
class LongestWord
{
public static void main(String args[])throws IOException
{
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter a String");
String s=in.readLine();
int l=s.length();
String wo="",w="";
s=s+" ";
int max=0,x;
for(int i=0;i {
char ch=s.charAt(i);
if(ch!=' ')
{
wo = wo+ch;
}
else
{
x=wo.length();
if(x>max)
{
max=x;
w=wo;
}
wo="";
}
}
System.out.println("Longes Word is " + wo);
}
}

Count the number of spaces in a String

This Program count the number of spaces in a String

import java.io.*;
class spaces
{
public static void main(String args[])throws IOException
{
int c=0;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter a String ");
String s = br.readLine();
int l= s.length();
for(int i=0;i{
char ch=s.charAt(i);
if(ch==' ')
c=c+1;
}
System.out.println("Number of spaces " + c);
}
}

Palindrom String

Check a String is palindrom or not

import java.io.*;
class palindrom
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter a String ");
String s = br.readLine();
int l=s.length();
String x = "";
int ch;
ch=0;
for(int i=l-1;i>=0;i--)
{
x=x+s.charAt(i);
}
if(x.compareTo(s)==0)
System.out.println(" its A palindrom");
else
System.out.println(" its not a palindrom ");
}
}

Pattern Alphabetic Diamond

A

A B

A B C

A B C D

A B C

A B

A

This is the output

class ABCD
{
public static void main(String a[])
{
char c;
for(int i=1;i<=7;i++)
{
int x = 65;
if(i<5)
{
for(int j = 4 ; j>=i;j--)
{
System.out.print(" ");
}
for(int k=1;k<=i;k++)
{
c=(char)x;
System.out.print(c + " " );
x=x+1;
}
}
else
{
for(int j=4;j<=i;j++)
{
System.out.print(" ");
}
for(int j=7;j>=i;j--)
{
c=(char)x;
System.out.print(c + " ");
x = x + 1;
}
}
System.out.println();
}
}
}

Pattern Inverted Triangle

+++++

++++

+++

++

+

this is the output of this program

class LeftTriangle
{
public static void main()
{
for(int i=0;i<5;i++)
{
for(int j=5;j>i;j--)
{
System.out.print("+");
}
System.out.println();
}
}
}

Pattern RightTriangle

1

12

123

1234

this will be printed By this program

class RightTriangle
{
public static void main()
{
for(int i=0;i<5;i++)
{
for(int j=1;j<=i;j++)
{
System.out.print(j);
}
System.out.println();
}
}
}

[2D array] TransPose of array

transpose

2 3 2 4
4 5 becomes 3 5



import java.io.*;
class Transpose
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a[][]=new int[2][3];
int b[][]=new int[3][2];
System.out.println(" Enter 6 elements for array one :");
for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
a[i][j]=Integer.parseInt(br.readLine());
}
}
System.out.println(" Matrix ");
for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
System.out.print(a[i][j]+"\t");
}
System.out.println();
}
System.out.println(" Trasposed ");
for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
b[j][i]=a[i][j];
}
}
for(int i=0;i<3;i++)
{
for(int j=0;j<2;j++)
{
System.out.print(b[i][j]+"\t");
}
System.out.println();
}
}
}

[2D array] Sum of Right Diagonal

Wap to find the Sum of Right Diagonal in a 2D Array

import java.io.*;
class SumDiagonalR
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a[][]=new int[3][3];
int Sum=0;
System.out.println(" Enter 6 elements for array one :");
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
a[i][j]=Integer.parseInt(br.readLine());
}
}
System.out.println(" Matrix ");
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
System.out.print(a[i][j]+"\t");
}
System.out.println();
}
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
if(i+j==2&&i!=j)
Sum = Sum + a[i][j];
}
}
System.out.println("Sum of Right Diagonal = "+Sum);
}
}

[2D array] Sum of left Diagonal

Wap a program to find the Sum of the Left diagonal of a 2D array

import java.io.*;
class SumDiagonal
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a[][]=new int[3][3];
int Sum=0;
System.out.println(" Enter 6 elements for array one :");
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
a[i][j]=Integer.parseInt(br.readLine());
}
}
System.out.println(" Matrix ");
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
System.out.print(a[i][j]+"\t");
}
System.out.println();
}
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
if(i==j)
Sum = Sum + a[i][j];
}
}
System.out.println("Sum of left Diagonal = "+Sum);
}
}

Find the Mean of the Array

import java.io.*;
class Mean
{
public static void main(String args[])throws IOException
{
int x[]=new int[10];
int a=0,i=0,j=0;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter 10 Values");
int sum=0,mean=0;
for(i=0;i<10;i++)
{
x[i]=Integer.parseInt(br.readLine());
sum=sum+x[i];
}
mean = sum/10;
System.out.println(" Mean = "+mean);
}
}

Search[Array]

WAP to find a particular element is a array and Display its position in the array

import java.io.*;
class PositionSearch
{
public static void main(String args[])throws IOException
{
int x[]=new int[10];
int a=0,i=0,j=0;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter 10 Values");
for(i=0;i<10;i++)
{
x[i]=Integer.parseInt(br.readLine());
}
System.out.println(" Enter the Value u want to search ");
int n=Integer.parseInt(br.readLine());
for(i=0;i<10;i++)
{
if(x[i]==n)
System.out.println(" the desired element is present at position " + i );
}
}
}

WAP to find the Max and Min element in a Array

import java.io.*;
class MaxMin
{
public static void main(String args[])throws IOException
{
int x[]=new int[5];
int a=0,i=0,j=0;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter 5 Values");
for(i=0;i<5;i++)
{
x[i]=Integer.parseInt(br.readLine());
}
int max,min;
max=x[0];
min=x[0];
for(i=0;i<5;i++)
{
if(x[i]>max)
max=x[i];
if(x[i]min=x[i];
}
System.out.println(" Max = " + max);
System.out.println(" Min = " + min);
}
}

Sort an array using Bubble sort technique

import java.io.*;
class BubbleSort
{
public static void main(String args[])throws IOException
{
int x[]=new int[5];
int a=0,i=0,j=0;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter 5 Values");
for(i=0;i<5;i++)
{
x[i]=Integer.parseInt(br.readLine());
}
for(i=0;i{
for(j=0;j{
if(x[j]>x[j+1])
{
a=x[j];
x[j]=x[j+1];
x[j+1]=a;
}
}
}
System.out.println("Result");
for(i=0;i<5;i++)
{
System.out.println(x[i]+"\t");
}
}
}

Sort an array using selection sort technique

import java.io.*;
class SelectionSort
{
public static void main(String args[])throws IOException
{
int x[]=new int[10];
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter 10 Integer values ");
for(int i=0;i<10;i++)
{
x[i] = Integer.parseInt(br.readLine());
}
int h,p=0;
for(int i=0;i{
h=x[i];
for(int j=i;j{
if(x[j]>h)
{
h=x[j];
p=j;
}
}
x[p]=x[i];
x[i]=h;
}
System.out.println(" After Sorting");
for(int i =0;i<=x.length-1;i++)
{
System.out.println(x[i]);
}
}
}

[2D array]Sum of Even and Odd

WAP a program to find the product of all the even elements and all the odd elements present in the array

//Wap to Store 12 elements in a array of size 3X4 and find the sum of all the elements
//and product of even elements and odd elements.

import java.io.*;
class EvenOdd
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a[][]=new int[3][4];
int s=0,even=1,odd=1;
System.out.println(" Enter 12 elements for array one :");
for(int i=0;i<3;i++)
{
for(int j=0;j<4;j++)
{
a[i][j]=Integer.parseInt(br.readLine());
s=s+a[i][j];
if(a[i][j]%2==0)
even=even*a[i][j];
else
odd=odd*a[i][j];
}
}
System.out.println(" Sum = " +s);
System.out.println(" Product of Even = " + even );
System.out.println(" Product of odd = " + odd);
}
}

Substraction Of 2D matrix

import java.io.*;
class MatrixSubs
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a[][]=new int[2][3];
int b[][]=new int[2][3];
int c[][]=new int[2][3];
System.out.println(" Enter 6 elements for array one :");
for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
a[i][j]=Integer.parseInt(br.readLine());
}
}
System.out.println(" Enter 6 elements for array 2 :");
for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
b[i][j]=Integer.parseInt(br.readLine());
c[i][j]=a[i][j]-b[i][j];
}
}

for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
System.out.print(c[i][j]+"\t");
}
System.out.println();
}
}
}

Addition Of 2D matrix

import java.io.*;
class Matrizadd
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a[][]=new int[2][3];
int b[][]=new int[2][3];
int c[][]=new int[2][3];
System.out.println(" Enter 6 elements for array one :");
for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
a[i][j]=Integer.parseInt(br.readLine());
}
}
System.out.println(" Enter 6 elements for array 2 :");
for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
b[i][j]=Integer.parseInt(br.readLine());
c[i][j]=a[i][j]+b[i][j];
}
}

for(int i=0;i<2;i++)
{
for(int j=0;j<3;j++)
{
System.out.print(c[i][j]+"\t");
}
System.out.println();
}
}
}

Smallest and Largest Digit present in a Number

Topic says the question


import java.io.*;
class LSdigits
{
public static void main(String args[])throws IOException
{
int i,x,num,n,l,h;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter any Number ");
num=Integer.parseInt(br.readLine());
n=num;
h=0;l=9;
do
{
x=n%10;
if(x>h)
h=x;
if(xl=x;
n=n/10;
}while(n>0);
System.out.println("Largest number = "+h+" Lowest number = " + l);
}
}

Frequency Of each Character of a String

import java.io.*;
class Frequency
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String s;
char ch ;
System.out.println("Enter a String ");
s=br.readLine();
for(int i=0;i{
int c=0;
ch=s.charAt(i);
for(int j=0;j{
if(s.charAt(j)==ch)
c++;
}
System.out.println(ch + " has " + c + " frequency ");
}
}
}

Fibonacci Series

import java.io.*;
class fibonacci
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int n,a=0,b=1,i,c;
System.out.println(" Enter any number ");
n = Integer.parseInt(br.readLine());
System.out.println(a+"\t"+b);
for(i=1;i<=n;i++)
{
c=a+b;
System.out.println("\t" +c);
a=b;
b=c;
}
}
}

Find the number with Highest number of Factors in a Array

Simple Prog

import java.io.*;
class NoFactor
{
public static void main(String args[])throws IOException
{
int x[]=new int[10];
int max=0,a=0,c=0;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter 10 integers");
for(int i=0;i<10;i++)
{
c=0;
x[i]=Integer.parseInt(br.readLine());
for(int j=1;j<=x[i];j++)
{
if(x[i]%j==0)
c++;
}
if(c>max)
{
a=x[i];
}
}
System.out.println("The number with highest number of factor = " + a +"with"+c+"factors");
}
}

Rupees To Dollar

import java.io.*;
class Dollar
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int a,r,d;
System.out.println(" the amount in rupees ");
a = Integer.parseInt(br.readLine());
System.out.println(" the rate of conversion into dollars ");
r = Integer.parseInt(br.readLine());
d = a/r;
System.out.println("the conversion into dollar " +d);
}
}

PrimePalindrom

This number checks wether a number is prime as well as palindrom

import java.io.*;
class Primepalindrom
{
public void accept()throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter a Number");
int n=Integer.parseInt(br.readLine());
Primepalindrom p = new Primepalindrom();
p.checkprime(n);
}
void checkprime(int n)
{
int i = 1;
double s=0;
int fact;
for(i=1;i<=n;i++)
{
if(n%i==0)
s=s+1;
}
if(s==2)
{
Primepalindrom p = new Primepalindrom();
p.checkpalindrom(n);
}
else
System.out.println("the number is not prime");
}
void checkpalindrom(int n)
{
int d,x,dup=0;
d=n;
do
{
x=d%10;
dup= dup*10+x;
d=d/10;
}
while(d>0);
if(dup==n)
System.out.println("The number is primepalindrom");
else
System.out.println("the number is not primepalindrom");
}
public static void main(String args[])throws IOException
{
Primepalindrom p = new Primepalindrom();
p.accept();
}
}

Covert Rupees To there Corresponding Notes

Easy One

import java.io.*;
class RupeesToNotes
{
public static void main(String args[])throws IOException
{
int amt,p20,p10,p5,p2,p1;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" enter the amount ");
amt = Integer.parseInt(br.readLine());
p20 = amt/20;
amt = amt%20;
System.out.println("20 X " + p20);
p10 = amt/10;
amt = amt%10;
System.out.println("10 X " + p10);
p5 = amt/5;
amt = amt%5;
System.out.println("5 X " + p5);
p2 = amt/2;
amt = amt%2;
System.out.println("2 X " + p2);
p1 = amt;
System.out.println("1 X " + p1);
}
}

PythaGorian Triplets

Like 5,4,3 are Pythagorian Triplets this programs Finds all

import java.io.*;
class triplet

{
public static void main()
{
int i,j,k;
for(i=1;i<=10;i++)
{
for(j=i+1;j<10;j++)
{
for(k=j+1;k<10;k++)
{
if((i*i)+(j*j)==(k*k))
{
System.out.println(i+" "+j+"and"+k+"are pyth. triplets");
}
}
}
}
}
}

Find Date

Short program Must know

import java.util.*;
class datefind
{
public void main()
{
Date dt = new Date();
System.out.println(" THE date is = " + dt);
}
}

[menudriven]-Area Of all the Shapes

import java.io.*;
class Ar
{
double a;
public void area(int x)
{
a = (3.14)*x*x;
System.out.println(" Area = " + a);
}
public void area()throws IOException
{
DataInputStream in = new DataInputStream(System.in);
int s;
System.out.println(" Enter side ");
s = Integer.parseInt(in.readLine());
a = s*s;
System.out.println(" area " + a);
}
public void area(float l,float b)
{
a = l*b;
System.out.println(" area = " + a);
}
public double area (int h,int p)
{
a = (0.5)*h*p;
return a;
}
public static void main(String args[])throws IOException
{
DataInputStream in = new DataInputStream(System.in);
System.out.println(" 1 : circle ");
System.out.println(" 2 : square ");
System.out.println(" 3 : rectangle ");
System.out.println(" 4 : triangle ");
System.out.println(" Enter your choice ");
int c;
Ar a1 = new Ar();
c = Integer.parseInt(in.readLine());
if(c==1)
{
int r;
System.out.println(" enter radius ");
r = Integer.parseInt(in.readLine());
a1.area(r);
}
else if(c == 2)
{
a1.area();
}
else if(c == 3)
{
float p,q;
System.out.println("enter length and breadth ");
p=Float.parseFloat(in.readLine());
q=Float.parseFloat(in.readLine());
a1.area(p,q);
}
else if(c == 4)
{
int y,z;
double d;
System.out.println(" enter base and hieght ");
y = Integer.parseInt(in.readLine());
z = Integer.parseInt(in.readLine());
d = a1.area(y,z);
System.out.println(d);
}
else
System.out.println(" Invalid ");
}
}


Its made using fuctions

HCF of a Number

Method Used :
The bigger of the two number is divided by the smaller one and remainder obtained. If the remainder is not 0 then the last divisor is divided by the remainder and another remainder is obtained . this goes on till the remainder is 0. when the remainder becomes 0,the number which is Devisor becomes HCF
Write a program To find the HCF of 2 number using above method

Evergreen Publications Model Paper unsolver Q5;

import java.io.*;
class HCF
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter any 2 numbers ");
int x = Integer.parseInt(br.readLine());
int y = Integer.parseInt(br.readLine());
int rem=1,re=1,h=1,s=1;
if(x>y)
{
h=x;
s=y;
}
else if(y>x)
{
h=y;
s=x;
}
do
{
rem =h%s;
if(rem>0)
{
re = s%rem;
s=rem;
rem = re;
}
else
{
System.out.println(s);
break;
}

}
while(rem>=0);

}
}

Prime Number

Here is a Program to find a number is prime or not

import java.io.*;
class prime
{
public static void main(String args[])throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter any no,");
int a = Integer.parseInt(br.readLine());
int fac=0;
for(int i =2;i{
if(a%i==0)
fac=1;
break;
}
if(fac==0)
System.out.println("Prime Number");
else
System.out.println("Not Prime Number");
}
}

Armstrong Number

Here is a Program to find out if a number is armstrong or not

import java.io.*;
class armstrongno
{
public static void main(String args[])throws IOException
{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int d,n,dup,sum=0;
System.out.println("Enter a NO.:");
n = Integer.parseInt(br.readLine());
for(dup=n;n>0;n/=10)
{
d=n%10;
sum = sum + d*d*d;
}
if (sum==dup)
System.out.println(dup+ " is an armstrong no.");
else
System.out.println(dup+ " is not an armstrong no.");
}
}