工厂方法模式

最新推荐文章于 2025-12-16 20:04:55 发布

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#工厂方法模式 #设计模式

本文介绍了一个使用工厂模式实现的简单计算器程序。通过定义抽象基类Operation及其实现加、减、乘、除操作的派生类，并利用IFactory接口创建不同类型的Operation对象，实现了灵活的算术运算功能。

#include <iostream>

using namespace std;

class Operation
{
    public:
        virtual double GetResult() = 0;
        void setA(double A)
        {
            m_numberA = A;
        }

        void setB(double B)
        {
            m_numberB = B;
        }

    protected:
        double m_numberA;
        double m_numberB;
};

class Add: public Operation
{
    double GetResult()
    {
        return (m_numberA + m_numberB);
    }
};

class Sub: public Operation
{
    double GetResult()
    {
        return (m_numberA - m_numberB);
    }
};

class Mul: public Operation
{
    double GetResult()
    {
        return (m_numberA * m_numberB);
    }
};

class Div: public Operation
{
    double GetResult()
    {
        if (m_numberB == 0)
        {
            cout << "m_numberB is 0" << endl;
            return -1;
        }

        return (m_numberA / m_numberB);
    }
};

class IFactory
{
    public:
        virtual Operation* CreateOperation() = 0; 
};

class AddFactory: public IFactory
{
    public:
        Operation* CreateOperation()
        {
            return new Add;
        }
};

class SubFactory: public IFactory
{
    public:
        Operation* CreateOperation()
        {
            return new Sub;
        }
};

class MulFactory: public IFactory
{
    public:
        Operation* CreateOperation()
        {
            return new Mul;
        }
};

class DivFactory: public IFactory
{
    public:
        Operation* CreateOperation()
        {
            return new Div;
        }
};

int main()
{
    IFactory* pFactory = new AddFactory;
    Operation* pOper = pFactory->CreateOperation();
    pOper->setA(11);
    pOper->setB(22);
    cout << pOper->GetResult() << endl;

    delete pFactory;
    delete pOper;

    return 0;
}