题解 | #多态实现计算器功能#

#include <iostream>
using namespace std;

class BaseCalculator {
    public:
        int m_A;
        int m_B;
        //声明getResult方法，并添加标识符virtual
        virtual int getResult();
};

// 加法计算器类
class AddCalculator : public BaseCalculator {
    //重载getResult方法，实现加法功能
    virtual int getResult(){
        return m_A+m_B;
    }
};

// 减法计算器类
class SubCalculator : public BaseCalculator {
    //重载getResult方法，实现减法功能
    virtual int getResult(){
        return m_A-m_B;
    }
};


int main() {

    BaseCalculator* cal = new AddCalculator;
    cal->m_A = 10;
    cal->m_B = 20;
    cout << cal->getResult() << endl;
    delete cal;

    cal = new SubCalculator;
    cal->m_A = 20;
    cal->m_B = 10;
    cout << cal->getResult() << endl;
    delete cal;

    return 0;
}