How can I truncate a number from the left in Java without using String

Question

I was wondering if anyone knew how to use mathematics to truncate a number from the left (remove digits one by one starting from the left).

I can use a simple division to truncate digits from the right:

int num = 10098;

while (num > 0){
    System.out.println(num);
    num /= 10;
}

This will output what I want:

10098
1009
100
10
1

But does anyone know a way to do this the other way around on integers and to truncate digits from the left without converting to String?

Answer 1

Try n = n % (int) Math.pow(10, (int) Math.log10(n));. Found here.

public void test() {
    int n = 10098;
    while (n > 0) {
        System.out.println("n=" + n);
        n = n % (int) Math.pow(10, (int) Math.log10(n));
    }
}

prints

n=10098
n=98
n=8