ZIG ZAG AND ZOOM understand a code please


#1

Hello, derrepente look silly this question but I wonder if someone can explain me this code because I believe this function

function mod15 (n){
while(n >= 15){
n -=15
}

return n
}

said generates a number between 0 and 15
but if I 0 to subtract income is not going to enter -15?


#2

If n == 0 then while(n >= 15){ doesnt call and function will return 0.