Find out factorial of Number.

package com.JavaInterview.Programs;

import java.util.*;

/**

 * Find Out Factorial of a number

 * 

 * @author:http://javainterviewprograms.blogspot.in/

 * 

 */

public class Factorial {

 public void findFactorial(int n) {

  int fact = 1;

  if (n < 0) {

   System.out.println("The Number should be non-negative");

  } else {

   for (int i = 1; i <= n; i++) {

    fact = fact * i;

   }

  }

  System.out.println("factorial Of Number  " + n + " is : " + fact);

 }

 public static void main(String[] args) {

  Scanner input = new Scanner(System.in);

  System.out.println("Please enter the number :");

  int num = input.nextInt();

  Factorial f = new Factorial();

  f.findFactorial(num);

 }

}

Output :

Please enter the number :

6

factorial Of Number  6 is : 720

Prints the numbers from 1 to 50 but for multiple of 3,5 print Fizz,Buzz,FizzBuzz.

package com.JavaInterview.Programs;

import java.util.*;

/* Write a Java program that prints the numbers from 1 to n. But for multiples of 

 * three print "Fizz" instead of the number and for the multiples of five print 

 * "Buzz". For numbers which are multiples of both three and five print "FizzBuzz"

 * Read more:http://javainterviewprograms.blogspot.in/

 * */

public class FizzBuzz {

 public void printFizzBuzz(int n)

 {

  for(int i=1;i<n;i++)

  {

   if(i%(3*5)==0)

   {System.out.println("FizzBuzz");}

   else if(i%3==0)

   {System.out.println("Fizz");}

   else if(i%5==0)

   {System.out.println("Buzz");}

   else

   {System.out.print(i+" ,");}

  }

 }

 public static void main(String args[])

 {

  Scanner input=new Scanner(System.in);

  System.out.println("Please enter the length of series");

  int num=input.nextInt();

 

  FizzBuzz fb=new FizzBuzz();

  fb.printFizzBuzz(num);

 }

}

Output:

Please enter the length of series

20

1 ,2 ,Fizz

4 ,Buzz

Fizz

7 ,8 ,Fizz

Buzz

11 ,Fizz

13 ,14 ,FizzBuzz

16 ,17 ,Fizz

19 ,

Program to replace character from the String using user defined method.

package com.JavaInterview.Programs;

/*How to replace characters from a string using user defined method .Here we have use  StringBuffer * ,you can also use StringBuilder.

*

* @author:http://javainterviewprograms.blogspot.in/
* 
*/
public class CharacterReplace2 {

 //User method to replace characters from a string

 public static String replace(String s,char from,char to)

 {

  StringBuffer str=new StringBuffer(s.length());

 

  for(int i=0;i<s.length();i++)

  {

   if(s.charAt(i)==from)

   {

    str.append(to);

   }

   else

   {

    str.append(s.charAt(i));

   }

  }

  return str.toString();

 }

 public static void main(String args[])

 {

  String original="This is a JIP Example String";

 

  System.out.println("Original String : "+original);

 

  

  String changed=replace(original, 'i','*');

 

  System.out.println("Changed String :" + changed);

 }

}

Output:

Original String : This is a JIP Example String

Changed String :Th*s *s a JIP Example Str*ng

Program to replace character from the String .

package com.JavaInterview.Programs;
/* How to get replace character or a string into a string with the given string. String provides replace() * method to replace a specific character or a string which occurs first. replaceAll() method replaces a *&specific character or a string at each occurrence. 
* @author:http://javainterviewprograms.blogspot.in/
*/

public class CharacterReplace {

public static void main(String args[])
{
String str="This is JIP Example String";

System.out.println("Original String : " + str);
//Replace one characters in string with another 
System.out.println("Replace Character 's' with 'x' :"+str.replace('s', 'x'));

//Replace first substring with another
System.out.println("Replace first substring 'is' with 'xy' :"+str.replaceFirst("is", "xy"));

//Replace all substring with another
System.out.println("Replace all substring 'is' with 'pp' :"+str.replaceAll("is", "pp"));
}

}

Output :

Original String : This is JIP Example String

Replace Character 's' with 'x' :Thix ix JIP Example String

Replace first substring 'is' with 'xy' :Thxy is JIP Example String

Replace all substring 'is' with 'pp' :Thpp pp JIP Example String

Swap Numbers

package com.JavaInterview.Programs;

import java.util.*;

/*

* @author:http://javainterviewprograms.blogspot.in/
* 
*/
public class SwapNumber {

 public void swap(int number1, int number2) {

  System.out.printf("Nmbers before Swap :" + number1 +","+ number2);

  number1 = number1 + number2;

  number2 = number1 - number2;

  number1 = number1 - number2;

  System.out.printf("Numbers after swap :" + number1+","+ number2);

 }

 public static void main(String args[]) {

  Scanner input1 = new Scanner(System.in);

  Scanner input2 = new Scanner(System.in);

  System.out.println("Please enter the number :");

  int num1 = input1.nextInt();

  int num2 = input2.nextInt();

  SwapNumber SN = new SwapNumber();

  SN.swap(num1, num2);

 }

}

Output :

Please enter the number :

23

54

Nmbers before Swap :23,54Numbers after swap :54,23

Sum of Prime Number

package com.JavaInterview.Programs;

import java.util.*;

/**
 * Find Out Factorial of a number
 * 
 * @author:http://javainterviewprograms.blogspot.in/
 * 
 */
public class SumOfPrime {

 public boolean isPrime(int number) {

  boolean status = true;

  for (int i = 2; i <= number / 2; i++) {

   if (number / i == 0) {

    status = false;

    break;

   }

  }

  return status;

 }

 public void sum(int totalCount)

 {

  int number=2;

  int sum=0;

  int count=0;

  while(count <   totalCount)

  {

   if(isPrime(number))

   {

    sum+=number;

    count++;

   }

   number++;

  }

 

  System.out.println("Sum of first "+totalCount +" Prime Number is :"+sum);

 }

 public static void main(String args[])

 {

  SumOfPrime SP=new SumOfPrime();

  Scanner input=new Scanner(System.in);

 

  System.out.println("Please enter lengthof Prime number that you want to add :");

  int count=input.nextInt();

  SP.sum(count);

 }

}

Output :

Please enter lengthof Prime number that you want to add :

12

Sum of first 12 Prime Number is :90

Sum Of Digits

package com.JavaInterview.Programs;

import java.util.Scanner;

/**
 * Find Out Factorial of a number
 * 
 * @author:http://javainterviewprograms.blogspot.in/
 * 
 */
public class SumOfDigit {

 int totalSum = 0;

 public int sum(int number) {

  if (number == 0) {

   return totalSum;

  } else {

   totalSum += (number % 10);

   sum(number / 10);

  }

  return totalSum;

 }

 public static void main(String args[]) {

  Scanner input = new Scanner(System.in);

  System.out.println("Please enter number :");

  int number = input.nextInt();

  SumOfDigit SD = new SumOfDigit();

  System.out.println("sum Of Digit of Number  " + number + " :"

    + SD.sum(number));

 }

}

Output:

Please enter number :

23

sum Of Digit of Number  23 :5