1.概念解析
2.示例代码
#include<bits/stdc++.h>
using namespace std;
class Operation
{
public:
Operation():_numberA(0), _numberB(0){ }
double GetNumberA()
{
return _numberA;
}
double SetNumberA(double value)
{
_numberA = value;
}
double GetNumberB()
{
return _numberB;
}
double SetNumberB(double value)
{
_numberB = value;
}
virtual double GetResult()
{
double result = 0;
return result;
}
private:
double _numberA;
double _numberB;
};
class OperationAdd:public Operation
{
double GetResult()
{
return GetNumberA() + GetNumberB();
}
};
class OperationSub:public Operation
{
double GetResult()
{
return GetNumberA() - GetNumberB();
}
};
class Factory
{
public:
static Operation* Create(char ioperator);
};
Operation* Factory::Create(char ioperator)
{
Operation *oper;
switch(ioperator)
{
case '+':
oper = new OperationAdd();
break;
case '-':
oper = new OperationSub;
break;
default:
oper = new OperationAdd();
break;
}
return oper;
}
int main()
{
int a,b;
char oper;
while(1)
{
cin>>a;
cin>>oper;
cin>>b;
Operation * op = Factory::Create(oper);
op->SetNumberA(a);
op->SetNumberB(b);
cout<<op->GetResult()<<endl;
}
return 0;
}
3.运行结果
