使用java.util.Hashtable出现错误？
import java.util.Hashtable;

public class UseHashtable{

public static void main(String[] args){

UseHashtable hScore= new UseHashtable();

hScore.put("张一","86");

hScore.put("李飞","98");

hScore.put("海飞","99");

System.out.println("修改成字符串之后输后输出:"+hScore.toString());

hScore.put("李二","77");

hScore.remove("张一");

System.out.println("修改之后的");



System.out.println("修改成字符串之后输后输出:"+hScore.toString());

}

}