1.简单工厂模式

UML类图

代码

main.cpp

#include <iostream>
#include "OperationFactory.h"
using namespace std;int main(void) {float num1;float num2;char operate;cin >> num1 >> num2 >> operate;Operation* oper = OperationFactory::createOperate(operate);oper->setnumA(num1);oper->setnumB(num2);double result = oper->getResult();cout << result << endl;return 0;
}

OperationFactory.h

#include"Operation.h"
#include<string>
using namespace std;
class OperationFactory {
public:static Operation* createOperate(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;}return oper;}
};

Operation.h

 class Operation {//运算类基类protected:float numA = 0;float numB = 0;public:void setnumA(float paramA) {numA = paramA;}void setnumB(float paramB) {numB = paramB;}virtual float getResult() {float result = 0;return result;}};class OperationAdd :public Operation {//加法类派生类public:float getResult() {float result = 0;result = numA + numB;return result;}};class OperationSub :public Operation {//派生减法类public:float getResult() {float result = 0;result = numA - numB;return result;}};class OperationMul :public Operation {//派生乘法类public:float getResult() {float result = 0;result = numA * numB;return result;}};class OperationDiv :public Operation {//派生除法类public:float getResult() {float result = 0;result = numA / numB;return result;}};