土妞 wrote:
class Calculator
{
int add(int x,int y)
{return x+y;}
}

class NewCalculator extends Calculator
{
double add(double x,double y)
{return x+y;}
}

public Test //public class Test
{public static void main(String[] args)
{Calculator c=new Calculator();
NewCalculator nc=new NewCalculator();
c.add(10,20);
nc.add(10,20); //这一句出错
}
}

这里应该构成了方法的重载,可是为什么出错呢?