Write a Java program to find the Area of the Circle, Rectangle and Triangle.

PROGRAM :

import java.util.*;

class area1

{

  

  public static void main(String[] args) throws InputMismatchException

  {

   Scanner sc = new Scanner(System.in);

   double area;

   

   System.out.println("Main Menu");

   System.out.println("1. Circle");

   System.out.println("2. Ractangle");

   System.out.println("3. Triangle");

   System.out.println("Enter your choice(1,2,3) : ");

   int ch;

   ch=sc.nextInt();

   switch(ch)

   {

    case 1:

         System.out.print("Enter the radius : ");

         double r=sc.nextDouble();

         area=r*r*3.14;

         System.out.println("\nThe area of Circle is : "+area);

         break;

    case 2:

         System.out.print("Enter the length : ");

         double l=sc.nextDouble();

         System.out.print("Enter the width :  ");

         double w=sc.nextDouble();

         area=l*w;

         System.out.println("\nThe area of Ractangle is : "+area);

         break;

    case 3:

         System.out.println("Enter sides of triangle : ");

         System.out.print("Enter side1 : ");

         double a=sc.nextDouble();

         System.out.print("Enter side2 : ");

         double b=sc.nextDouble();

         System.out.print("Enter side3 : ");

         double c=sc.nextDouble();

         double s=(a+b+c)/2;

         area=Math.sqrt(s*(s-a)*(s-b)*(s-c));

         System.out.println("\nThe area of Triangle is : "+area);

         break;

    default:

         System.out.println("Wrong choice !!!");

         break;

    }

  }

}

Java Program To Find The Frequency Of Each Digit In A Given Number. | JAVA POINT

 

Write a Java program to find the frequency of each digit in a given number.

PROGRAM :

import java.util.Scanner;

 

public class freq

{

 public static void main(String[] args)

 {

  Scanner sc=new Scanner(System.in);

  System.out.println("Enter the number to be checked.");

  int i,j,c;

  int n=sc.nextInt();

  System.out.println("No Freq");

  for(i=0;i<=n;i++)

  {

   c=0;

   for(j=n;j>0;j=j/10)

   {

    if(j%10==1)

    c++;

   }

 

  if(c>0)

   System.out.println("Freq of  "+i+" is "+c);

 }}

}

/*

Output :

Enter the number to be checked : 12121

Freq of 1 is 4 

Freq of 2 is 2

Java Program to Check the Armstrong numbers | JAVA POINT Numbers

Java Program to Check the Armstrong numbers 

Armstrong number

Armstrong number

A number will be called Armstrong if the sum of cubes of each digits is equal to the original number.

Program

import java.util.Scanner;

public class Armstrong

{

    public static void main(String args[])

    {

        Scanner ob=new Scanner(System.in);

        System.out.println("Enter the number to be checked.");

        int num=ob.nextInt();

        int a,i,sum=0;

        i=num;

        while(num!=0) 

        {

            a=num%10;

            sum=sum+a*a*a;

            num=num/10;

          }

          if(sum==i)

              System.out.println(i+" is an Armstrong Number.");

          else

              System.out.println(i+" is not a Armstrong Number.");

    }

}

/*

Output :

Enter the number to be checked : 153

153 is an Armstrong Number.

(Workings 153 = 1*1*1 + 5*5*5 + 3*3*3)

*/

Also read :

Prime numbers in Java

Java program to print the words starting with a Consonant | JAVA POINT

Write a Java program to enter a sentence and print the words starting with a Consonant

PROGRAM :

import java.util.*;

class print_consonant

{

   public static void main(String args[])

   {

        Scanner sc=new Scanner(System.in);            

        System.out.println("Enter any sentence: ");

        String s=sc.nextLine();

        s = s+" ";

        int l=s.length();

        int pos=0;

        char ch1, ch2;

        String w;

        for(int i=0; i<l; i++)

        {

            ch1 = s.charAt(i);

            if(ch1 == ' ')

            {

                w = s.substring(pos,i); // extracting words one by one

                ch2 = w.charAt(0);

                if(ch2=='A' || ch2=='E' || ch2=='I' || ch2=='O' || ch2=='U' || ch2=='a' || ch2=='e' || ch2=='i' || ch2=='o' || ch2=='u')

          pos = i+1;                    

                else

          System.out.print(w+" ");

          pos = i+1;

            }

        }

   }

}

/*

 Output :

 Enter any sentence: He is a boy

 He boy

*/

Java program to Check the Disarium Number

Java program to check the Special number | JAVA POINT

Write a Java program to check that a given number is Special number or not.

Special number

If the sum of the factorial of each digit of a number (N) is equal to the number itself, the number (N) is called a Special number or Peterson number or Krishnamurthy Number. 

PROGRAM :

import java.util.Scanner;

public class specialnum
{
 public static void main(String[] args)
 {
        
    int n, num, r,
    sum = 0;
    Scanner sc=new Scanner(System.in);
    System.out.print("Enter the number to check : ");
    n = sc.nextInt();
    num = n;
    while (num > 0)
    {
      r = num % 10;
      int fact=1;
      for(int i=1;i<=r;i++)
      {
        fact=fact*i;
      }
      sum = sum+fact;
            num = num / 10;
    }
    if(n==sum)
    {
     System.out.println("Special Number" );
     }
     else
     {
       System.out.println("Not Special Number" );
        }
    }

}

/*

Output :

Enter the number to be checked : 145

( 145=1!+4!+5!=1+24+120=145 )

145 is a Special number.

*/

Java Program to print the Prime number

Java program to check the Neon Number | JAVA POINT

 

Write a Java program to check that a given number is Neon number or not.

Neon number

A number is said to be a Neon Number if the sum of digits of the square of the number is equal to the number itself.

PROGRAM :

import java.util.*;

public class neon

{

    public static void main(String args[])

    {

        Scanner ob=new Scanner(System.in);

        System.out.print("\nEnter the number to be checked : ");

        int num=ob.nextInt();

        int square=num*num;

        int sum=0;

        while(square!=0)//Loop to find the sum of digits.

        {

            int a=square%10;

            sum=sum+a;

            square=square/10;

        }

        if(sum==num)

        {

            System.out.println(num+" is a Neon Number.");

        }

        else

        {

            System.out.println(num+" is not a Neon Number.");

        }

    }

}

/*

Output :

Enter the number to be checked : 9

 9 is a Neon Number.

(Workings 9*9=81 sum of digits of square = 8 + 1 = 9.)

*/

Java Program to Print the Consonant words

Java program for Armstrong numbers

Java Program To Find The Frequency Of Each Digit In A Given Number

Java program to check the DISARIUM number | JAVA POINT

 

Write a Java program to check that a given number is  DISARIUM number or not.

DISARIUM number

A number will be called DISARIUM if sum of its digits powered with their respective position is equal to the original number.

PROGRAM :

import java.util.Scanner;

class disarium

{ 

  public static void main(String[] args)

  {

   Scanner sc=new Scanner(System.in);

   System.out.print("\nEnter the number to be checked : ");

   int n=sc.nextInt();

   int copy = n, d = 0, sum = 0;

   String s = Integer.toString(n); //converting the number into a String

   int len = s.length(); //finding the length of the number i.e. no.of digits

       

   while(copy>0)

   {

    d = copy % 10; //extracting the last digit

    sum = sum + (int)Math.pow(d,len);

    len--;

    copy = copy / 10;

   }

             

   if(sum == n)

     System.out.println(n+" is a Disarium Number.");

   else

     System.out.println(n+" is not a Disarium Number.");

  }

}

/*

Output :

Enter the number to be checked : 135

135 is a Disarium Number.

(Workings 1+3*3+5*5*5 = 1+9+125 = 135

other DISARIUM are 89, 175, 518 etc)

*/

Java program to check the Neon Number

Java program to insert an element into an array at given position

Java program to insert an element into the array | JAVA POINT

Write a Java program to insert an element into the array.

PROGRAM :

import java.util.*;
class arrinsert
{  
 public static void main(String[] args)
 {
  int n,pos,x;

  Scanner sc=new Scanner(System.in);
  System.out.print("\nEnter size of array : ");
  n=sc.nextInt();

  int a[]=new int[n+1];

  System.out.print("\nEnter all the elements of array : \n");
  
  System.out.println();

  for(int i=0; i<n; i++)
  {
   a[i]=sc.nextInt();
  }

  System.out.println("\nBefore insertion the array is :");

  for(int i=0; i<n; i++)
  {
   System.out.print(a[i]+" ");
  }

  System.out.println();

  System.out.print("\nEnter the position where you want to insert the element: ");
  pos=sc.nextInt();

  System.out.print("\nEnter the element you want to insert : ");
  x=sc.nextInt();

  for(int i=(n-1); i>=(pos-1); i--)
  {
   a[i+1]=a[i];
  }
  a[pos-1]=x;

  System.out.println("\nAfter insertion");

  for(int i=0; i<n; i++)
  {
   System.out.print(a[i]+",");
  }
  System.out.print(a[n]);
 }
}

/*

Output :

Enter size of array : 5

Enter all the elements of array : 

4 6 2 6 7 

Before insertion the array is :

4 6 2 6 7 

Enter the position where you want to insert the element: 3

Enter the element you want to insert : 8

After insertion

4,6,8,2,6,7

*/

Java Program to display all the Prime numbers between 1 and n

Write a Java Program to display all the prime numbers between 1 to n (the number n is entered by user).

Prime Numbers

Prime numbers are the numbers that have only two factors, that are, 1 and the number itself.

PROGRAM :

import java.util.Scanner;

class PrimeNumbers
{
   public static void main (String[] args)
   {
      Scanner scanner = new Scanner(System.in);
      int i =0;
      int num =0;

      String  primeNumbers = " ";

      System.out.println("Enter the value of n:");
      int n = scanner.nextInt();

      for (i = 1; i <= n; i++)     
      {   
         int counter = 0;

  
         for(num =i; num>=1; num--)
         {
    if (i%num == 0)
    {
counter = counter + 1;
    }
}

if (counter == 2)
{ 
    primeNumbers = primeNumbers + i + " "; 

           //Appended the Prime number to the String
}
      }

      System.out.println("Prime numbers from 1 to n are :");
      System.out.println(primeNumbers);
   }
}

/*

Output:

Enter the value of n:

100

Prime numbers from 1 to n are :

2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 

*/

Java Program to check the Special Number

Java program for the pattern of 'E' | Patterns in JAVA | JAVA POINT

 

Ques : Write a java program for following Pattern of  'E' :

     * * * * 

            *                 

     *         

     * * * * 

     *         

             *                 

     * * * * 

PROGRAM :

import java.util.Scanner;

public class PatternE

{

    public static void main(String[] args)

    {

        System.out.print("Enter the number of      

        rows : ");.                // 7

        Scanner scan=new Scanner(System.in);

        int n=scan.nextInt();

        System.out.println();

        for (int i=0;i<n ;i++ )

        {

            for (int j=0;j<=n/2 ;j++ )

            {

                if (i==0 || i==n-1 || i==n/2 || j==0)

                {

                    System.out.print("* ");

                }

                else

                {

                    System.out.print("  ");

                }

            }

            System.out.println();

        }

    }

}

Java program for the pattern of 'B' | JAVA Patterns | JAVA POINT

 

Ques : Write a Java Program for the following pattern 'B'

* * * *

* *

* *

* *

* * * *

* *

* *

* *

* * * *

PROGRAM :

import java.util.Scanner;
public class PatternB
{
public static void main(String[] args)
{
System.out.print("Enter the number of
rows : ");. // 9
Scanner scan=new Scanner(System.in);
int n=scan.nextInt();
System.out.println();
for (int i=0;i<n ;i++ )
{
for (int j=0;j<=n/2 ;j++ )
{
if (i==0 && j!=n/2 || j==0 || j==n/2 &&
i!=0 && i!=n/2 && i!=n-1 || i==n/2
&& j!=n/2 || i==n-1 && j!=n/2)
{
System.out.print("* ");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}