Question

I’m trying to add all the digits in an integer value until i get a value below 9 using Javascript.

for an example, if i have 198, I want to add these together like 1 + 9 + 8 = 18, and since 18 is higher than 9 add 1 +8 again = 9.

Answer 1

Rather than giving you full code I would just explain how to do it.

You can do modulo math by number%10 and subsequent int divide by 10 (number/10) until you get 0 to get all the digits of a number. Sum the individual digits and until sum > 9 repeat the above process in a loop.

Edit: okay here is the code for you:

<script>
var num=198;
n = num;
var sum;
do {
   sum = 0;
   while (n>0) {
      rem = (n % 10);
      sum += rem;
      n = (n - rem)/10;    
   }
   n = sum;
} while(sum>9);

alert("sum is: " + sum);

</script>