public?class?HelloWorld{
public?static?void?main(String[]?args){
int?num?=?999;
int?count?=?0;
//num是要判斷位數(shù)的數(shù)字
//先判斷num是大于0的?并且是9位數(shù)以下的
if(num?>=0?&&?num<=999999999)
{
?//利用了java語言中整型數(shù)據(jù)截斷小數(shù)部分的特點
?//對num進(jìn)行/10?
?//999/10?=99?
?//?99/10=9
?//?9/10?=0?
?//count是用來存儲/10的數(shù)次?除了三次?num的值才為0
?//那么num的位數(shù)就是3
?while(num!=0)
????{
????????count++;
????????num/=10;
????}
????System.out.println("它是個"+count+"位的數(shù)！");
????
????}
????else
????{
???????System.out.println("輸入有誤");
????}

錯誤信息

error:?reached?end?of?file?while?parsing
}
^
1?error