Java day08 异常（2）

class NegativeException extends ArithmeticException
{
NegativeException(String msg)
{
super(msg);
}
}
//若在方法体中抛出非RuntimeException,而在方法上没有声明该异常，则发生编译错误
class Div
{
int div(int a,int b)
{
if(b<0)
throw new NegativeException("除数是负数");
else if(b==0)
throw new RuntimeException("除以了0");
else
return a/b;
}
}
class RuntimeDemo
{
public static void main(String[] args)
{
Div d=new Div();
d.div(4,0);

}
}