Looping Programs Excercise

1) 1 1 1 1 1

for(let i=1;i<=5;i++)
{
    document.write(1+" ");

}

Output :  1 1 1 1 1

2) 1 2 3 4 5

for(let i=1;i<=5;i++)
{
    document.write(i+" ");

}

Output : 1 2 3 4 5

3) 1 3 5 7 9

for(let i=1;i<=10;i+=2)
{
  document.write(i+" ");

}

Output : 1 3 5 7 9

4) 3 6 9 12 15

for(let i=3;i<=15;i+=3)
{
  document.write(i+" ");

}

Output : 3 6 9 12 15

5) Multiples of 3 and 5

let str = "";

for(let i=3;i<=100;i++)
{
    if(i%3 ==0 && i%5 ==0)
        str += i+", ";

}
document.write("Multiplies of 3 and 5 upto 100 : "+ str.slice(0,-2));

Output : 

Multiplies of 3 and 5 upto 100 : 15, 30, 45, 60, 75, 90

6) Multiples of 3 or 5

let str = "";

for(let i=3;i<=100;i++)
{
    if(i%3 ==0 || i%5 ==0)
        str += i+", ";

}
document.write("Multiplies of 3 or 5 upto 100 : "+ str.slice(0,-2));

Output : 

Multiplies of 3 or 5 upto 100 : 3, 5, 6, 9, 10, 12, 15, 18, 20, 21, 24, 25, 27, 30, 33, 35, 36, 39, 40, 42, 45, 48, 50, 51, 54, 55, 57, 60, 63, 65, 66, 69, 70, 72, 75, 78, 80, 81, 84, 85, 87, 90, 93, 95, 96, 99, 100

7) Divisors of given number

let number = 20;
let str = "1, ";

for(let i=2;i<number;i++)
{
    if(number%i==0)
    str+= i+", ";

}

str += number;
document.write(`Divisors of given number ${number} is : `+str);

8) Count of Divisors of given number

let number = 20;
let count = 2;

for(let i=2;i<number;i++)
{
    if(number%i==0)
       count++;

}

document.write(`Count of Divisors of given number ${number} is : `+count);

9) Prime Number - number greater than 1 whose only divisors are 1 and itself.

for(let i=2 ; i<100 ;i++)
{
    let isPrime = true;
    for(let j=2 ; j<i ; j++){

    if(i%j ==0)
        isPrime = false;
    }

    if (isPrime)
    document.write(i+" ");

}

Output : 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

10) Reverse Printing a number

let number = 23497;
let revisedNumber =0;
let remainder = 0; 

while(number>0)
{

    remainder = (number%10);
    revisedNumber = revisedNumber*10+remainder;
    number = parseInt(number/10);
}

 document.write(revisedNumber);

Output :  79432

11) Count of Digits

let number = 23497;
let count = 0;

while(number>0)
{
    number = parseInt(number/10);
    count++;
}

document.write(count);

Output : 5

12) Sum of Digits

let number = 23497;
let sumOfNumbers =0;
let remainder = 0; 

while(number>0)
{

    remainder = (number%10);
    sumOfNumbers +=remainder;
    number = parseInt(number/10);
}

 document.write(sumOfNumbers);

Output : 25

14) Palindrome -an integer that remains the same when its digits are reversed

let originalNumber = 101;
let number = originalNumber
let reverseNumber =0;
let remainder = 0; 

while(number>0)
{


    remainder = (number%10);
    reverseNumber = (reverseNumber*10)+remainder;
    number = parseInt(number/10);

}

if(originalNumber === reverseNumber)
    document.write(`${reverseNumber} is a palindrome number`);
else
    document.write(`${reverseNumber} is not a palindrome number`);

15) Armstrong Number -integer that equals the sum of its own digits, each raised to the power of the total number of digits

let originalNumber = 407;
let number2 = originalNumber;
let digitCount = findDigitCount(153);
let sumOfDigit = 0;

function findDigitCount(originalNumber)
{
    let number = originalNumber;
    let digit = 0;
    while(number>0)
    {
        number = parseInt(number/10);
        digit++;
    }

    return digit;
}


function findPowerOfDigit(value,digitCount)
{

    return value**digitCount;
}


while(number2>0)
{

    sumOfDigit = sumOfDigit+findPowerOfDigit(number2%10,digitCount);
    number2 = parseInt(number2/10);

}


if(sumOfDigit === originalNumber)
document.write(`Given number ${originalNumber} is an Armstrong Number`);
else
document.write(`Given number ${originalNumber} is not an Armstrong Number`);

16) Neon Number - the sum of digits of square of the number is equal to the number.

for(let i=0;i<=100;i++)
{
let sumOfDigit = 0;
let no = i**2;
while(no>0)
{
 sumOfDigit = sumOfDigit + (no%10);
 no = parseInt(no/10);

}
if (i == sumOfDigit)
document.write(`${i} is a Neon Number <br>`)
}

17) Strong Number - number whose sum of the factorial of its digits is equal to the original number.

Factorial of a Number : the product of all positive integers less than or equal to the number.

let origNumber = 145;
let number = origNumber;
let remainder = 0
let total = 0;


while(number>0)
{
 total = total+findFactorial(number%10);

 number = parseInt(number/10);
}

function findFactorial(remainder)
{
let factorialofNumber = 1;
    for(let i = remainder; i>=2;i--)
    {

    factorialofNumber =  factorialofNumber*i;
    }
    return factorialofNumber;

}
if(origNumber == total)
document.write(`Given number ${origNumber} is a Strong Number`);
else
document.write(`Given number ${origNumber} is not a Strong Number`);

18) Addition of first n numbers

let number = 15;
let total = 0;
for(let i=1; i<=number;i++)
{
total+= i;
}

document.write(total);

19) Factorial

let number = 6;
let factorialNumber = 1;
for(let i=1; i<=number;i++)
{
factorialNumber = factorialNumber*i;
}

document.write(factorialNumber);

20) Greatest Common Divisor

let number1 = 30;
let number2 = 15;
let GCD = 0;

for (let i = 2;i <= (number1<number2?number1:number2) ; i++)
{
if(number1%i ==0 && number2%i ==0)

GCD = i;
}

document.write(GCD);