设计模式C++实现一：简单工厂模式

来源：互联网发布：淘宝创想电玩编辑：程序博客网时间：2024/05/17 11:36

参考大话设计模式和网上的一些资料，自己编写下一些简单的设计模式，让自己了解这些设计模式的妙处！

#ifndef OPERATION_H#define OPERATION_H#include<iostream>using namespace std;class Operation{protected:double opA, opB;public:bool SetValue(double& n, double& m);virtual double GetResult()const=0;};class OperationAdd :public Operation{double GetResult()const;};class  OperationSub :public Operation{double GetResult()const;};class OperationMul :public Operation{double GetResult()const;};class OperationDiv :public Operation{double GetResult()const;};class OperationFactory{public:Operation * CreatOperation(char& operate);};bool Operation::SetValue(double &n, double &m){opA = n;opB = m;return true;}double OperationAdd::GetResult()const{double result;result = opA + opB;return result;}double OperationSub::GetResult()const{double result;result = opA - opB;return result;}double OperationMul::GetResult()const{double result;result = opA * opB;return result;}double OperationDiv::GetResult()const{if (opB == 0){ cout << "opB in OperationDiv can't be zero.\n"; return 0.00000001;}double result;result = opA / opB;return result;}Operation * OperationFactory::CreatOperation(char& operate){Operation * Oper = NULL;switch (operate){case('+') :Oper = new OperationAdd;break;case('-') :Oper = new OperationSub;break;case('*') :Oper = new OperationMul;break;case('/') :Oper = new OperationDiv;break;default:break;}return Oper;}#endif

#include"operation.h"int main(){double numA, numB;char op;Operation * Oper;OperationFactory OpFa;cout << "Please enter the numbers and operation(A op B)";while (cin>>numA&&cin>>op&&cin>>numB){Oper = OpFa.CreatOperation(op);Oper->SetValue(numA, numB);cout << "The result of " << numA << op << numB << "= " << Oper->GetResult() << endl;cout << "Please enter the numbers and operation(A op B)";}return 0;}

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