public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count = 0;
if (num==0){
    System.out.println("它是个1位的数！");}
if (num>0 && num<=999999999){
    while (num!=0){
        count++;
        num=num/10;
    }
    System.out.println("它是个"+ count+"位的数！");

}
}
}

//用这个代码可以解决0是0位的问题