C++抽象类实践

实践如下：

#include <iostream>
using namespace std;

class Service {

public:
    // 有一个虚函数即为抽象类
    int id;
    // 不定义虚析构函数 会报右侧异常：@suppress("Class has a virtual method and non-virtual destructor")
    virtual ~Service(){}
    virtual double calc()=0;
    int aa(){
        return 11;
    }
};

class AService: public Service {
public:
    //virtual ~AService(){}
    double calc() {
        // 操作抽象类中定义的字段
        id = 100;
        cout << "id：" << id << endl;

        cout << "AService 100~~~" << endl;
        return 100;
    }
};
class BService: public Service {
public:
    //virtual ~BService(){}
    double calc() {
        cout << "BService 200~~~" << endl;
        return 200;
    }
};

int main() {

    cout << "抽象类 实践：" << endl;

    Service *s = new AService();
    s->calc();

    cout << "
抽象类 end." << endl;

    return 0;
}

结果：