public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count = 0;
if( num <= 9999999999 ){
while(num != 0){
count++;
num/=10;
}
System.out.println("他是"+count+"位数");
} else{
System.out.println("数据错误");
}
}
}
要小于十位数才行
long
9999999999太大了