设计模式-简单工厂模式（实现，可与前文进行比较）

代码贴上，需要的自己看吧。废话就不多说了，差别在代码里，关于学术型的语言大家还是看一下技术解析贴把，我就不做赘述了。这里主要是为大家提供代码的区别// 这里才是 工厂函数的精髓#include <iostream>#include <string>using namespace std;class Operation {private: double _numberA; double _numberB;public: //Operation(){}; double getNumberA(){ return _numberA; } void setNumberA(int value){ _numberA = value; } double getNumberB(){ return _numberB; } void setNumberB(int value){ _numberB = value; } virtual double getResult(){ double result=0; return result; }};class OperationAdd:public Operation{private: public: double getResult(){ double result=0; result = getNumberA()+getNumberB(); return result; }};class OperationSub:public Operation{private: public: double getResult(){ double result=0; result = getNumberA()-getNumberB(); return result; }};class Factory:public Operation {public: // 因为需要返回一个算法 Operation* createFactory(string str){ Operation* ope; char* a = new char[100]; // 为什么这里写成 new char() 下面ope就不能初始化?，有没有哪位知道的回一下哦，谢了 strcpy(a, str.c_str()); cout<<"size of a = "<<sizeof(a)<<endl; //?? 为什么是8 不应该是4 么，mac下是8，windows看情况 cout<<"lenth a = "<<strlen(a)<<endl; cout<<"a[0] ="<<a[0]<<endl if="" sizeof="" a="">0){ switch (a[0]) { case '+': delete a; ope = new OperationAdd(); break; case '-': ope = new OperationSub(); break; default: break; } } return ope; }};int main(int argc, const char * argv[]) { // insert code here... std::cout << "Hello, World!\n"; Operation* ope = new Operation(); Factory* fac = new Factory(); string str; str = "+++++++++++++++++++++++++++++++++++++++++++"; ope = fac->createFactory(str); ope->setNumberA(6); ope->setNumberB(5); cout<<ope->getResult()<<endl; delete fac; delete ope; return 0;}</ope-></endl></string></iostream>