Pls explain this code block.

Question

var a = 423;
var sum = 0;

while(a >0){
sum += a % 10;
a = Math.round(a/10);
}
console.log(sum);

Answer 1

This block of code sums the individual integers in a number. For this example, that is 3 + 2 + 4.

Every time through the loop sum is added to itself plus the remainder of a divides by 10.
423 % 10 = 3
Then a becomes itself divided by 10, and actually this should be:
Math.floor(a / 10)
because if the number was 426, it would round 42.6 to 43.

So now a becomes 42. 42 % 10 is 2, sum = 3 + 2 = 5, and a becomes floor(4.2) which is 4.

4 % 10 is 4, sum = 5 + 4 = 9, and then floor (0.4) is zero and then the loop breaks.

Answer 2

Here! It is pretty detailed. Go straight to the JS tab and read the comments. Like Jay said, they are just getting and adding the digits of the number

https://code.sololearn.com/WMZa2aZdGP6n/?ref=app