请问这是哪里出问题了呢?有点混乱,求指导
public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count = 0;
do{
System.out.println("它是个"count++"位的数!");
do{
num/=10;
count++;
}while(num >0 && num < 999999999);
}while( num > 0 );
}
}