c++多态案例之计算器类

#include<iostream>
using namespace std;

//普通写法,如果想扩展，需要修改源码
在实际开发中，提倡开闭原则，对扩展进行开发，对修改进行关闭
class Calculator {
public:
    int num1;
     num2;
    int getResult(string oper) {
        if (oper == "+"){
            return num1 + num2;
        }
        else -) {
            return num1 -*return num1 */return num1 /else
        {
            return -1;
        }
    }
};
利用多态实现计算器
 AbstractCalculator {
virtual  getResult() {
        return 0;
    }
};
class Add : AbstractCalculator {
     num2;
    }
};
class Sub :class Mul :class Div :void test() {
    Calculator cal;
    cal.num1 = 6;
    cal.num2 = 3;
    int res = cal.getResult();
    cout<< res << endl;
}
 test2() {
    AbstractCalculator * cal = new Add;
    cal->num1 = ;
    cal->num2 = ;
    cout << 加法：" << cal->getResult() << endl;
    delete cal;
    cal =  Div;
    cal->num1 = 除法： endl;
    delete cal;
}

 main() {
    test2();
    system(pause);
    ;
}