C++day5（静态成员、类的继承、多继承）

一、Xmind整理：

二、上课笔记整理：

1.静态数据成员+静态成员函数（银行账户实例）

#include <iostream>using namespace std;class BankAccount
{
private:double balance;   //余额static double interest_rate;   //利率
public://无参构造函数BankAccount (){}//有参构造函数BankAccount(double balance):balance(balance){}//静态成员函数,获取当前利率static double getInterestRate(){return interest_rate;}//静态成员函数，设置当前利率、static double setInterestRate(double rate){interest_rate = rate;}//静态成员函数，获取连本带利的全额static double getLastMoney(BankAccount &account){return account.balance*(1+interest_rate);}
};double BankAccount::interest_rate = 0.05;int main()
{cout << "当前利率：" << BankAccount::getInterestRate() << endl;BankAccount::setInterestRate(0.03);cout << "当前利率：" << BankAccount::getInterestRate() << endl;BankAccount account1(2000.0);BankAccount account2(3000.0);cout << "第一个人连本带利的余额为：" << BankAccount::getLastMoney(account1) << endl;return 0;
}

2.类的继承

#include <iostream>using namespace std;//封装 人  类  父类/基类
class Person
{
private:string name;
protected:int age;
public:int h;
public://无参构造函数Person(){cout << "父类的无参构造函数" << endl;}//有参构造Person(string name, int age, int h):name(name),age(age),h(h){cout << "父类的有参构造函数" << endl;}//拷贝构造函数Person(const Person & other):name(other.name),age(other.age),h(other.h){cout << "父类的拷贝构造函数"  << endl;}//拷贝赋值函数Person & operator=(const Person &p){name = p.name;age = p.age;h = p.h;cout << "父类的拷贝赋值函数" << endl;return  *this;}void show(){cout << "父类的show" << endl;}
};//封装 学生 类   共有继承人 类
class Stu:public Person   //子类 、派生类
{
private:int id;int math;public://无参构造函数Stu(){cout << "子类的无参构造函数" << endl;}//有参构造函数Stu(string name, int age, int h, int id, int math):Person(name,age,h),id(id),math(math){cout << "子类的有参构造函数" << endl;}//拷贝构造函数Stu(const Stu & s):id(s.id),math(s.math),Person(s){cout << "子类的拷贝构造函数" << endl;}//拷贝赋值函数Stu & operator=(const Stu & s){Person::operator=(s);id = s.id;math = s.math;cout << "子类的拷贝赋值函数" << endl;return *this;}void show(){cout << "子类的show" << endl;cout << h << endl; //通过共有继承，类外、子类可以访问父类共有成员cout << age << endl; //通过共有继承，子类可以访问父类保护成员,类外不可以访问//cout << name << endl;//通过共有继承，子类不可访问父类私有成员,类外不可以访问}
};int main()
{Stu s("zhangsan",12,190,1001,78);Stu s2=s;Stu s3;s3 = s2;//    s.show();
//    s.Person::show();return 0;
}

3.多继承

#include <iostream>using namespace std;class Sofa
{
private:string sitting;
public://无参构造函数Sofa(){cout << "沙发的无参构造" << endl;}//有参构造函数Sofa(string s):sitting(s){cout << "沙发的有参构造" << endl;}void display(){cout << sitting << endl;}
};class Bed
{
private:string sleep;
public://无参构造函数Bed(){cout << "床的无参构造" << endl;}//有参构造函数Bed(string(s)):sleep(s){cout << "床的有参构造" << endl;}void display(){cout << sleep << endl;}
};class Sofa_Bed:public Bed,public Sofa
{
private:int w;
public://无参构造函数Sofa_Bed(){cout << "沙发床的无参构造" << endl;}//有参构造函数Sofa_Bed(string sit, string s, int w):Bed(s),Sofa(sit),w(w){cout << "沙发床的有参构造" << endl;}
};
int main()
{Sofa_Bed(s);Sofa_Bed s1("可坐","可躺",123);s1.Sofa::display();s1.Bed::display();return 0;
}