how to know the number of digits in number c code example

Example 1: print digits of a number in c

#include <stdio.h>

int main(){
    int num = 1024;

    while(num != 0){
        int digit = num % 10;
        num = num / 10;
        printf("%d\n", digit);
    }
  
    return 0;
}

Example 2: c how many digits has a number

digits = (number == 0) ? 1 : (log10(number) + 1);
//or
while (number > 0)
{
	number /= 10;
	digits++;
}
//see: https://ideone.com/P1h8Ne