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+"位數(shù)");

} else{

? ? System.out.println("數(shù)據(jù)錯誤");

}

}

}