计算正整数各位数的和---345

import java.util.Scanner;
class Demo5 
{
public static void main(String[] args) 
{
//计算正整数各位数的和---345
        Scanner sc = new Scanner(System.in);
        int sum = 0,num;




System.out.println("输入一个正整数");
num = sc.nextInt();


        while(num!=0)
{
sum = sum+num%10;
num = num/10;
}
        System.out.println("sum="+sum);
}
}