#include <iostream>
using namespace std;
class Person
{
public:
	void Print()
	{
		cout << "name:" << _name << endl;
		cout << "age:" << _age << endl;
	}
protected:
	string _name = "peter"; // 姓名
	int _age = 18; // 年齡
};
// 繼承后父類的Person的成員（成員函數+成員變量）都會變成子類的一部分。這里體現出了
//Student和Teacher復用了Person的成員。
class Student : public Person
{
protected:
	int _stuid; // 學號
};
 
class Teacher : public Person
{
protected:
	int _jobid; // 工號
};
int main()
{
	Student s;
	Teacher t;
	s.Print();
	t.Print();
	return 0;
}

#include <iostream>
using namespace std;
class Person
{
protected:
	string _name; // 姓名
	string _sex; // 性別
	int _age; // 年齡
};
class Student : public Person
{
public:
	int _No; // 學號
};
void Test()
{
	Student sobj;
	// 1.子類對象可以賦值給父類對象/指針/引用
	Person pobj = sobj;
	Person* pp = &sobj;
	Person& rp = sobj;
 
	//2.基類對象不能賦值給派生類對象
	//sobj = pobj;
	
	// 3.基類的指針可以通過強制類型轉換賦值給派生類的指針
	pp = &sobj;
	Student * ps1 = (Student*)pp; // 這種情況轉換時可以的。
	ps1->_No = 10;
	pp = &pobj;
	Student* ps2 = (Student*)pp; // 這種情況轉換時雖然可以，但是會存在越界訪問的問題
	ps2->_No = 10;
}

// Student的_num和Person的_num構成隱藏關系，可以看出這樣代碼雖然能跑，但是非常容易混淆
class Person
{
protected:
	string _name = "小李子"; // 姓名
	int _num = 111; // 身份證號
};
class Student : public Person
{
public:
	void Print()
	{
		cout << " 姓名:" << _name << endl;
		cout << " 身份證號:" << Person::_num << endl;
		cout << " 學號:" << _num << endl;
	}
protected:
	int _num = 999; // 學號
};
void Test1()
{
	Student s1;
	s1.Print();
};
 
// B中的fun和A中的fun不是構成重載，因為不是在同一作用域
// B中的fun和A中的fun構成隱藏，成員函數滿足函數名相同就構成隱藏。
class A
{
public:
	void fun()
	{
		cout << "func()" << endl;
	}
};
class B : public A
{
public:
	void fun(int i)
	{
		A::fun();
		cout << "func(int i)->" << i << endl;
	}
};
void Test2()
{
	B b;
	b.fun(10);
};
int main()
{
	Test1();
	Test2();
	return 0;
}

class Person
{
public:
	Person(const char* name = "peter"): _name(name)
	{
		cout << "Person()" << endl;
	}
 
	Person(const Person& p)	: _name(p._name)
	{
		cout << "Person(const Person& p)" << endl;
	}
 
	Person& operator=(const Person & p)
	{
		cout << "Person operator=(const Person& p)" << endl;
		if (this != &p)
		{
			_name = p._name;
		}
		return *this;
	}
 
	~Person()
	{
		cout << "~Person()" << endl;
	}
 
protected:
	string _name; // 姓名
};
class Student : public Person
{
public:
	Student(const char* name, int num): Person(name), _num(num)
	{
		cout << "Student()" << endl;
	}
 
	//派生類的拷貝構造函數必須調用基類的拷貝構造完成基類的拷貝初始化
	Student(const Student& s): Person(s), _num(s._num)
	{
		cout << "Student(const Student& s)" << endl;
	}
 
	//派生類的operator=必須要調用基類的operator=完成基類的復制
	Student& operator = (const Student& s)
	{
		cout << "Student& operator= (const Student& s)" << endl;
		if (this != &s)
		{
			Person::operator =(s);
			_num = s._num;
		}
		return *this;
	}
 
	~Student()
	{
		cout << "~Student()" << endl;
	}
 
protected:
	int _num; //學號
};
void Test()
{
	Student s1("jack", 18); 
	Student s2(s1);
	Student s3("rose", 17);
	s1 = s3;
}
 
int main()
{
	Test();
	return 0;
}

class Person
{
public:
	Person() 
	{
		++_count;
	}
protected:
	string _name; // 姓名
public:
	static int _count; // 統(tǒng)計人的個數。
};
int Person::_count = 0;
 
class Student : public Person
{
protected:
	int _stuNum; // 學號
};
class Graduate : public Student
{
protected:
	string _seminarCourse; // 研究科目
};
void TestPerson()
{
	Student s1;
	Student s2;
	Student s3;
	Graduate s4;
	cout << " 人數 :" << Person::_count << endl;
	Student::_count = 0;
	cout << " 人數 :" << Person::_count << endl;
}
 
 
int main()
{
	TestPerson();
	return 0;
}

class Person
{
public:
	string _name; // 姓名
};
 
class Student : virtual public Person
{
protected:
	int _num; //學號
};
 
class Teacher : virtual public Person
{
protected:
	int _id; // 職工編號
};
 
class Assistant : public Student, public Teacher
{
protected:
	string _majorCourse; // 主修課程
};
 
void Test()
{
	Assistant a;
	a._name = "peter";
}
 
int main()
{
	Test();
	return 0;
}

class A
{
public:
	int _a;
};
// class B : public A
class B : virtual public A
{
public:
	int _b;
};
// class C : public A
class C : virtual public A
{
public:
	int _c;
};
class D : public B, public C
{
public:
	int _d;
};
int main()
{
	D d;
	d.B::_a = 1;
	d.C::_a = 2;
	d._b = 3;
	d._c = 4;
	d._d = 5;
	return 0;
}