哪错了呀 看了好几遍没看出来 求解
public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count = 0;
if(num>=0 && num<=999999999){
while(num!=0){
count++;
num/=10;
}
System.out.println("它是个"+ count +"位的数!");
}
else
System.out.println("输入错误.");
}
}