这个程序有错误是什么原因，怎么解决？

Question

package hi;
import java.util.Scanner;
public class Hi{
       public static void main(String[] args){
         Scanner in=new Scanner(System.in);
          int a =in.nextInt();
          while()
           {
            }
}
}

Eclipse中while那一行显示错误，Syntax error on token"(",Expression expected after this token

Answer 1

while(这里得添加判断条件)
{
}
while循环小括号中添加循环条件