除數為0了就不該有返回值了，應該手動拋出異常！
public?class?Manager{
public?double?div(double?x,double?y)
{
try{
if(y==0)
{
throw?new?ArithmeticException();
}
else
return?x/y;
}catch(ArithmeticException?ae)
{
ae.printStackTrace();
System.out.println("除數為0");
}
return?x/y;
}
public?static?void?main(String?ar[])
{
Manager?m=new?Manager();
System.out.println(m.div(10,?0));
}
}
運行結果：