每日打卡-1-JZTXT

一.定义一个哺乳动物Mammal类，再由此派生出狗Dog类，定义一个Dog类的对象，观察基类与派生类的构造函数与析构函数的调用顺序。

1.我们按照题目要求写出对应代码，然后观察输出结果来确定调用顺序就好了。

3.伪代码：

类 mammal{
public：
构造函数(){输出}
private:
age weight；
};
类 dog: public mammal{
public:
构造函数(){输出}
private:
name color
}；
main(){
dog a;
return 0;
}

代码：

#include<iostream>
using namespace std;
class Mammal {

protected:
    int age, weight;
public:
    Mammal() :age(1), weight(5) { cout << "Mammal constructor..." << endl; }
    ~Mammal() { cout << "Mammal destructor..." << endl; }

    const int getage() {
        return age;
    }
    void setage(int a) {
        age = a;
    }
    const int getweight() {
        return weight;
    }
    void steweight(int a) {
        weight = a;
    }
};
class dog :public Mammal{

private:
    string color;
    string name;
public:
    dog():color("white"), name("xiaobai") { cout << "dog constructor..." << endl; }
    ~dog(){ cout << "dog destructor..." << endl; }
    string getcolor() {
        return color;
    }
    void setcolor(string s) {
        color = s;
    }
    string getname() {
        return name;
    }
    void setname(string s) {
        name = s;
    }
};
int main() {
    dog xiaobai;
    cout << "xiaobai is " << xiaobai.getage() << " years old" << endl;
    return 0;
}

4.总结：先调用基类的构造函数再调用派生类对象的构造函数