簡單工廠模式實現粗略的四則運算

頭文件：

Factory.h

#ifndef FACTORY_H
#define FACTORY_H

#include "product.h"

class Factory
{
public:
    Factory();
    Product *getProduct(enum Type type);
};

#endif // FACTORY_H

Product.h

#ifndef PRODUCT_H
#define PRODUCT_H

enum Type{PA,PB,PC,PD};

class Product
{
public:
    Product();
    virtual int Operation(int a,int b)=0;
};

class ProductA:public Product
{
public:
    int Operation(int a, int b);
};

class ProductB:public Product
{
public:
    int Operation(int a, int b);
};
class ProductC:public Product
{
public:
    int Operation(int a, int b);
};
class ProductD:public Product
{
public:
    int Operation(int a, int b);
};

#endif // PRODUCT_H

源文件：

Factory.c

#include "factory.h"

Factory::Factory()
{
}

Product *Factory::getProduct(Type type)
{
    switch (type) {
    case PA:
        return new ProductA;
        break;
    case PB:
        return new ProductB;
        break;
    case PC:
        return new ProductC;
        break;
    case PD:
        return new ProductD;
        break;
    default:
        break;
    }
}

Product.c

#include "product.h"

Product::Product()
{
}


int ProductA::Operation(int a, int b)
{
    return a+b;
}


int ProductB::Operation(int a, int b)
{
    return a-b;
}


int ProductC::Operation(int a, int b)
{
    return a*b;
}


int ProductD::Operation(int a, int b)
{
    return a/b;
}

mian.c

#include <iostream>
#include "factory.h"

using namespace std;

int main()
{
    cout << "Hello World!" << endl;

    Factory *f = new Factory;
    cout << f->getProduct(PA)->Operation(30,20);
    return 0;
}