Programs on java loops(while)

Programs on Loops important to crack interview

Palindrome

Armstrong

Even/Odd

Perfect Number

Fibnacci series

Reversing a number

package com.loops;
public class Checkingloops {

public static void main(String[] args) {
// TODO Auto-generated method stub
int i = 10;

while (i>=1) {
System.out.println("The value of i is: "+i);
i--;
}

}

}

class CheckingWhileEven {
public static void main(String[] args) {
int i =0;
while (i<=10) {

i += 2;
System.out.println("The value of i is: "+i);
}
}
}

class CheckingWhileOdd {
public static void main(String[] args) {
int i = 1;
while (i<=10) {
System.out.println("The value of i is: "+i);
i += 2;

}
}
}

class CheckingWhileMultiples {
public static void main(String[] args) {
int i = 1;
while (i<= 10) {
System.out.println("The multple of 5 with "+i+": "+(5*i));
i++;
}
}
}

class CheckingWhileSum {
public static void main(String[] args) {
int i = 1,sum = 0;
while (i<= 10) {
sum = sum + i;
System.out.println("The value of sum for every: "+i+" "+sum);
i++;
}
}
}

class CheckingWhileFactorial {
public static void main(String[] args) {
int i = 1,factorial = 1;
while (i <= 5) {
factorial = factorial*i;
i++;
}
System.out.println("The factorial value is:"+factorial);
}
}

class WhileEvenIf{
public static void main(String[] args) {
int i =0;
while (i<= 10) {
if (i%2 == 0) {
System.out.println("The value of i is: "+i);
}
i++;
}
}
}

class WhileOddIf {
public static void main(String[] args) {
int i = 0;
while(i<=10) {
if(i%2 == 1) {
System.out.println("The value of i is: "+i);
}
i++;
}
}
}

class WhileEvenSum {
public static void main(String[] args) {
int i=0,sum = 0;
while(i<=10) {
if(i%2 == 0) {
sum = sum +i;
}
i++;
}
System.out.println("The sum of even numbers is: "+sum);
}
}

class WhileOddSum {
public static void main(String[] args) {
int i = 1,sum = 0;
while(i<=10) {
if(i%2 == 1) {
sum = sum + i;
}
i++;
}
System.out.println("The value of i is: "+sum);
}
}

class WhileFactors {
public static void main(String[] args) {
int i = 1, factors = 6;
while (i <= factors) {
if (factors%i == 0) {
System.out.println("The factors of "+factors+" is : "+i);
}
i++;
}
}
}

class WhilePerfect {
public static void main(String[] args) {
int i = 1, factor = 6, sum = 0, perfectNumber = 0;
while ( i<= factor) {
if (factor%i == 0) {
sum = sum + i;
}
i++;
}
perfectNumber = sum - factor;
if (perfectNumber == factor) {
System.out.println("Pefect Number "+ perfectNumber);
}
}
}

class WhileFactorCount {
public static void main(String[] args) {
int i =1,factor = 6, count = 0;
while (i <= factor) {
if ( factor%i == 0) {
count++;
}
i++;
}
System.out.println("The number of factors are: "+count);
}
}

class WhilePrime {
public static void main(String[] args) {
int i = 1, number = 7, count = 0;
while (i<= number) {
if (number%i == 0) {
count++;
}
i++;
}
if(count == 2) {
System.out.println("This is prime number");
} else {
System.out.println("This is not prime number");
}
}
}

class WhileFibonacci {
public static void main(String[] args) {
int firstDigit = 0, secondDigit = 1, sum = 0, number = 1;
while(number <= 5) {
sum = firstDigit + secondDigit;
firstDigit = secondDigit;
secondDigit = sum;
System.out.println("The fibonacci Series is: "+sum);
number++;
}

}
}

class WhileDigits{
public static void main(String[] args) {
int number = 12345, remainder = 1, quotient = 1;
while (number != 0) {
remainder = number%10;
quotient = number/10;
number = quotient;
System.out.println(remainder);
}
}
}

class WhileDigitSum {
public static void main(String[] args) {
int number = 3245, remainder = 1, quotient = 1, sum = 0;
while (number != 0) {
remainder = number%10;
quotient = number/10;
number = quotient;
sum = sum + remainder;
}
System.out.println("The Sum of digits is :"+sum);
}
}

class WhileDigitCube {
public static void main(String[] args) {
int number = 145, remainder = 1, quotient = 1, sum = 0;
while (number != 0) {
remainder = number%10;
quotient = number/10;
number = quotient;
sum += remainder*remainder*remainder;
}
System.out.println("The sum of cubes of digits is: "+sum);
}
}

class WhileArmstrong {
public static void main(String[] args) {
int number = 153, finalNumber = 153, remainder = 1, quotient = 1, sum = 0;
while (number != 0) {
remainder = number%10;
quotient = number/10;
number = quotient;
sum += remainder*remainder*remainder;
}
if (finalNumber == sum) {
System.out.println("The sum of cubes of digits is: "+sum);
}
}
}

class WhileReverseNumber {
public static void main(String[] args) {
int number = 123,remainder = 1,quotient =1;
String sum = "";
while (number != 0) {
remainder = number % 10;
quotient = number / 10;
number = quotient;
sum += remainder;
}
System.out.println("The Reverse of given number is :"+sum);
}
}

/*class WhilePalindrome {
public static void main(String[] args) {
int number = 121, remainder = 1, quotient = 1;
String palindrome = "";
while (number != 0) {
remainder = number % 10;
quotient = number / 10;
number = quotient;
palindrome += remainder;
}

}
}
Palindrome
reverse of a number equal to original number
121*/