继承的知识点（1）

//private：除了本身类内其余类不可调用
//protected：本身与派生类可以调用
//public：都可以调用
//例程

#include <iostream>
#include <string>
#include <windows.h>

using namespace std;

class people
{
private:
   string m_name;
   int m_age;

public:
   void setpeople(string name, int age);
   void showinfo();
};

void people::setpeople(string name, int age)
{
   m_name = name;
   m_age = age;
}

void people::showinfo()
{
   cout << "名字是：" << m_name << endl;
   cout << "年龄是：" << m_age << endl;
}

class student : public people
{
private:
   int m_id;
public:
   void setid(int id);
   void print();
};

void student::setid(int id)
{
   m_id = id;
}

void student::print()
{
   cout << "学号是：" << m_id << endl;
}

int main()
{
   student s1;
   s1.setpeople("tqn", 21);
   s1.setid(202150225);

   s1.showinfo();
   s1.print();

   system("pause");
   return 0;
}

//地址分配上先分配继承来的后分配自己声明的

#include <iostream>

#include <windows.h>

using namespace std;

class A
{
public:
   int m_a;
   int m_b;
   A();
   ~A();
};
A::A()
{
   cout << "constuctor A ok~" << endl;
}

A::~A()
{
   cout << "destuct A ok~" << endl;
}

class B :public A
{
public:
   int m_c;
   B();
   ~B();
};

B::B()
{
   cout << "constuctor B ok~" << endl;
}
B::~B()
{
   cout << "destuct B ok~" << endl;
}

int main()
{
   B b1;
   cout << &b1.m_a << endl;
   cout << &b1.m_b << endl;
   cout << &b1.m_c << endl;
   system("pause");
   return 0;
}

//初始化的时候构造的顺序是父类 --> 成员 --> 自己这个是语法规定的没有为什么

#include <iostream>

#include <windows.h>

using namespace std;

class A
{
public:
   int m_a;
   int m_b;
   A(int a);
   ~A();
   void printA();
};
A::A(int a)
{
   cout << "constuctor A ok~" << endl;
   m_a = a;
}

A::~A()
{
   cout << "destuct A ok~" << endl;
}

void A::printA()
{
   cout << m_a << endl;
}

class C
{
public:
   int m_c;
   C(int c);
};

C::C(int c)
{
   m_c = c;
   cout << "constuctor C ok~" << endl;
}

class B :public A
{
public:
   int m_c;
   B(int b);
   ~B();
   void printB();
   C c;
   const int d;
};

B::B(int b) : A(b), c(b) , d(b)//初始化列表这个顺序无所谓
{
   cout << "constuctor B ok~" << endl;
   m_b = b;
}

B::~B()
{
   cout << "destuct B ok~" << endl;
}

void B::printB()
{
   cout << m_b << endl;
}

int main()
{
   B b1(1);
   b1.printA();
   b1.printB();

   system("pause");
   return 0;
}

类的继承中父类子类出现同名成员变量依然继承只是调用的时候调用自己的

#include <iostream>

#include <windows.h>

using namespace std;

class A
{
public:
   int m_a;
   int m_b;

};

class B :public A
{
public:
   int m_b;
   int m_c;
};

int main()
{
   B b1;
   cout << sizeof(b1) << endl;
   cout << &b1.m_a << endl;
   cout << &b1.m_b << endl;
   cout << &b1.A::m_b << endl;
   cout << &b1.m_c << endl;
   system("pause");
   return 0;
}

继承的知识点（1）

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