Hello guys, i need help, why here output 23?

Question

var sum = 0;
for (i=1; i<=9; i++) {
if (i%5 === 0 || i%3 === 0) {
sum+=i;
}
}
document.write(sum);

Answer 1

(javascript question)

It makes sense

3+5+6+9 =23

the sum of the 0 - 9 values that = 0 remainder when divided by 3 and 5