C++类对象初始化记录

//java
Biumall biumall_1; //只是定义变量
biumall_1 = new Biumall(); // 此时才初始化
Biumall biumall_2 = new Biumall(101);

//C++
Biumall biumall_1;  //定义并且初始化，调用了Biumall()
Biumall biumall_2(101); // 调用了Biumall(int age) 

class Biumall {
public: //必须，C++默认为private
    Biumall() {
        std::cout << "Biumall()--->biumall.com\n";
    }
};

int main()
{
    //初始化无参构造函数
    Biumall biumall;
}

Biumall biumall;

class Biumall {
public:
    Biumall(int age) {
        std::cout << "Biumall(age)--->biumall.com age : "<< age <<std::endl;
    }
};

int main()
{
    Biumall biumall(5);
}

class Biumall {
private:
    int age;
public:
    Biumall() {
        age = 5;
        std::cout << "Biumall()--->biumall.com  "<< std::endl;
    }
​
    Biumall(const Biumall& biumall) {
        age = biumall.age;
        std::cout << "Biumall(const Biumall& biumall)--->biumall.com  " << age << std::endl;
    }
};

int main()
{
    Biumall biumall1;
    Biumall biumall2 = biumall1;
}