7月24日上课笔记：
遇到有两个类 Birthday和Student同时都有含参数的构造函数，且在Student类中私有变量为Birthday m_birth；
Birthday(int y, int m, int d); //有参数的构造参数
Birthday.cpp
#include <iostream>
using namespace std;
class Birthday
{
private:
int m_year;
int m_month;
int m_day;
public:
Birthday(int y, int m, int d); //有参数的构造参数
void print();
~Birthday();
};
Birthday::Birthday(int y, int m, int d) //带参构造函数
{
m_year = y;
m_month = m;
m_day = d;
cout << "Birthday constructor!" << endl;
}
Birthday::~Birthday() //析构函数
{
cout << "Birthday destruct!" << endl;
}
void Birthday::print()
{
cout << "birthday:" << m_year << " " << m_month << " " << m_day << endl;
}
class Test
{
private:
int m_a;
public:
Test(int a);
~Test();
};
Test::Test(int a) //带一个参数的构造函数
{
cout << "Test constructor!" << endl;
m_a = a;
}
Test::~Test()
{
cout << "Test destruct!" << endl;
}
class Student
{
private:
Birthday m_birth; //对象作为私有变量
Test t;
char name[20];
const int age;
public:
Student(char *n, int y, int m, int d); //这里的参数要包括Birthday构造函数里的参数，即y，m，d
void print();
~Student();
};
Student::Student(char *n, int y, int m, int d):m_birth(y, m, d),age(20),t(d)
//对象初始化列表Student参数中的y，m，d是给了Birthday中的构造函数的参数
{
cout << "Student constructor!" << endl;
strcpy(name, n);
}
Student::~Student()
{
cout << "Student destruct!" << endl;
}
void Student::print()
{
cout << "name:" << name << endl;
cout << "age:" << age << endl;
m_birth.print();
}
int main()
{
Student s1("zys",1998,1,1);
s1.print();
return 0;
}
构造函数的调用顺序与初始化列表顺序无关，跟对象声明的顺序有关
执行结果：
