Java开发网 - 关于java继承的问题?

Topic: 关于java继承的问题?

1.关于java继承的问题?

Posted by: 土妞
Posted on: 2005-04-21 20:53

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 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?

2.Re:关于java继承的问题? [Re: 土妞]	Copy to clipboard
Posted by: why Posted on: 2005-04-21 21:40 I don't see any problem with overloading the add method ... okay, here's an unrelated issue: public class Test What's the compilation error you received? Are you sure it's really 这一句出错?

3.Re:关于java继承的问题? [Re: 土妞]

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Posted by: kaiserlew
Posted on: 2005-04-22 01:05

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?

add方法是有返回值的
int a=c.add(10,20);
double b=nc.add(10,20);
System.out.print(a+" "+b+" ");

4.Re:关于java继承的问题? [Re: 土妞]	Copy to clipboard
Posted by: wddodo Posted on: 2005-04-22 08:37 public " class" Test

5.Re:关于java继承的问题? [Re: 土妞]	Copy to clipboard
Posted by: 土妞 Posted on: 2005-04-23 15:45 后来我发现,在jdk1.3.0下编译通不过,在jdk1.4下却能运行.难道是jdk版本的问题?