Dh01-Simple Factory mode

Introduction to Patterns

The simple Factory mode, also known as the static factory method pattern, defines an interface for creating objects. Its main components are:

1. Factory class role: The core of the model, with certain business logic and judgment logic. As the class in the exampleAnimalSpecies
2. Abstract Product Role: The parent class of the specific product inheritance or implementation interface. As the class in the exampleAnimal
3. Specific product roles: the object created by the factory class is an instance of this role. such as the class in the example Cat ,Dog

Class Diagram Analysis

Program code

#include <iostream>using namespace std;class Animal{public:    virtual void showMessage()=0;//基类不在基类中实现纯虚函数的方法是在函数原型后加“=0”};class Cat :public Animal{public:    Cat(){}    void showMessage()    {        cout << "i am cat" << endl;    }};class Dog :public Animal{public:    Dog(){}    void showMessage()    {        cout << "i am dog" << endl;    }};class AnimalSpecies{public:    Animal *createAnimal(const char *name)    {        if (strcmp(name, "cat")==0) //1、== 返回0  2、>返回正数 3、<返回负数        {            return new Cat();        }        else if (strcmp(name,"dog")==0)        {            return new Dog();        }       }};int main(){    AnimalSpecies *as=new AnimalSpecies();    Animal *dog=as->createAnimal("dog");    Animal *cat = as->createAnimal("cat");    dog->showMessage();    cat->showMessage();    system("pause");    return 0;}

Resources

Simplified design mode (Chinese version): Http://wenku.baidu.com/view/8fb442ce0508763231121206.html?from=search

Dh01-Simple Factory mode