C++ 类继承：Base 和 Derived 类的构造与析构顺序

以下是代码实现：

#include <iostream>

class Base {
private:
    int x;
public:
    Base(int x) : x(x) {
        std::cout << 'Base constructor called' << std::endl;
    }
    ~Base() {
        std::cout << 'Base destructor called' << std::endl;
    }
};

class Derived : public Base {
private:
    int y;
public:
    Derived(int x, int y) : Base(x), y(y) {
        std::cout << 'Derived constructor called' << std::endl;
    }
    ~Derived() {
        std::cout << 'Derived destructor called' << std::endl;
    }
};

int main() {
    Derived d(1, 2);
    return 0;
}

程序的输出结果为：

Base constructor called
Derived constructor called
Derived destructor called
Base destructor called

这是因为在创建 Derived 对象时，首先会调用 Base 的构造函数，然后再调用 Derived 的构造函数。当程序结束时，会先调用 Derived 的析构函数，再调用 Base 的析构函数。