浅析简单工厂模式--C++代码实现
//运算操作基类
class COperation
{
public:
int m_nFirst;
int m_nSecond;
virtual double GetResult() //返回操作结果
{
double dResult=0;
return dResult;
}
};
//加法
class AddOperation : public COperation
{
public:
virtual double GetResult()
{
return m_nFirst+m_nSecond;
}
};
//减法
class SubOperation : public COperation
{
public:
virtual double GetResult()
{
return m_nFirst-m_nSecond;
}
};

//工厂类，为了方便我用的静态函数
class CCalculatorFactory
{
public:
static COperation* Create(char cOperator);
};

COperation* CCalculatorFactory::Create(char cOperator)
{
COperation *oper;
//在C#中可以用反射来取消判断时用的switch，在C++中用什么呢？我觉得是RTTI，后面可以讲到
switch (cOperator)
{
case '+':
oper=new AddOperation();
break;
case '-':
oper=new SubOperation();
break;
default:
oper=new AddOperation();
break;
}
return oper;
}

//客户端
int main()
{
int a,b;
cin>>a>>b;
COperation * op=CCalculatorFactory::Create('-');
op->m_nFirst=a;
op->m_nSecond=b;
cout<<op->GetResult()<<endl;
return 0;
}