課程

/后端開發

/Java

/Java入門第一季（IDEA工具）升級版

public?class?HelloWorld{
public?static?void?main(String[]?args){
????int?num?=?999;
	int?count?=?0;
	do{count++;
	???num=num/10;
	???}while(num!=0);
		System.out.println("它是個"+count+"位的數!");








}
}