答案一样，但是为什么显示运行成功，输出错误呢？求大佬解答
public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count = 0;
while (num>0 && num<1000000000) {
num /= 10;
count++;
}
System.out.println("它是个"+count+"位的数");
}
}
