[C/C++]继承

公有继承 class Worker:public Person

练习题：

#include <iostream>#include <stdlib.h>#include <string>using namespace std;/** * 定义人的类: Person * 数据成员姓名: m_strName * 成员函数: eat() */class Person{public:    string m_strName;void eat(){cout << "eat" << endl;}};/** * 定义士兵类: Soldier * 士兵类公有继承人类: public * 数据成员编号: m_strCode * 成员函数: attack() */class Soldier:public Person{public:string m_strCode;void attack(){cout << "fire!!!" << endl;}};int main(void){    // 创建Soldier对象Soldier soldier;    // 给对象属性赋值    soldier.m_strName = "Jim";soldier.m_strCode = "592";    // 打印对象属性值cout << soldier.m_strName << endl;cout << soldier.m_strCode << endl;    // 调用对象方法soldier.eat();soldier.attack();return 0;}

保护继承 class Worker:protected Person

私有继承 class Worker:private Person

继承中的特殊关系

隐藏 （相当于 JAVA 的 重写）

注意：子类函数与父类名称相同即构成隐藏，跟参数没有关系

练习题：

#include <iostream>#include <stdlib.h>#include <string>using namespace std;/** * 定义人类: Person * 数据成员: m_strName * 成员函数: attack() */class Person{public:    string m_strName;void attack(){cout << "attack" << endl;}};/** * 定义士兵类: Soldier * 士兵类公有继承人类 * 数据成员: m_strName * 成员函数: attack() */class Soldier:public Person{public:string m_strName;void attack(){cout << "fire!!!" << endl;}};int main(void){    // 实例士兵对象Soldier soldier;    // 向士兵属性赋值"tomato"    soldier.m_strName = "tomato";    // 通过士兵对象向人类属性赋值"Jim"soldier.Person::m_strName = "Jim";    // 打印士兵对象的属性值cout << soldier.m_strName << endl;    // 通过士兵对象打印人类属性值cout << soldier.Person::m_strName << endl;    // 调用士兵对象方法soldier.attack();    // 通过士兵对象调用人类方法    soldier.Person::attack();return 0;}

多重继承

class Person {}

class Worker:public Person{}

class Soldier:public Worker{}

多继承

class Person{}

class Worker{}

class Soldier : public Person, public Worker {}

练习题：

#include <iostream>#include <stdlib.h>#include <string>using namespace std;/** * 定义工人类: Worker * 数据成员: m_strName * 成员函数: work() */class Worker{public:    Worker(string name){m_strName = name;cout << "Worker" << endl;}~Worker(){cout << "~Worker" << endl;}void work(){cout << m_strName << endl;cout << "work" << endl;}protected:string m_strName;};/** * 定义儿童类: Children * 数据成员: m_iAge * 成员函数: play() */class Children{public:Children(int age){m_iAge = age;cout << "Children" << endl;}~Children(){cout << "~Children" << endl;}void play(){cout << m_iAge << endl;cout << "play" << endl;}protected:int m_iAge;};/** * 定义童工类: ChildLabourer * 公有继承工人类和儿童类 */class ChildLabourer : public Worker, public Children{public:ChildLabourer(string name, int age):Worker(name),Children(age){cout << "ChildLabourer" << endl;}~ChildLabourer(){cout << "~ChildLabourer" << endl;}};int main(void){    // 使用new关键字创建童工类对象ChildLabourer *pc = new ChildLabourer("小明", 12);    // 通过童工对象调用父类的work()和play()方法pc->work();    pc->play();    // 释放    delete pc;    pc = NULL;return 0;}

虚继承 virtual

class A : virtual public B {}

class C : virtual public B {}

解决父类被多个子类继承，造成重定义问题的方法：

#ifndef PERSON_H#define PERSON_H#pragma once#include <string>using namespace std;class Person{public:Person();~Person();void eat();string m_strName;string m_iAge;};#endif // !PERSON_H

#include <iostream>#include <stdlib.h>#include <string>using namespace std;/** * 定义人类: Person */class Person{public:    Person(){cout << "Person" << endl;}~Person(){cout << "~Person" << endl;}void eat(){cout << "eat" << endl;}};/** * 定义工人类: Worker * 虚继承人类 */class Worker : virtual public Person{public:Worker(string name){m_strName = name;cout << "Worker" << endl;}~Worker(){cout << "~Worker" << endl;}void work(){cout << m_strName << endl;cout << "work" << endl;}protected:string m_strName;};/** * 定义儿童类:Children * 虚继承人类 */class Children : virtual public Person{public:Children(int age){m_iAge = age;cout << "Children" << endl;}~Children(){cout << "~Children" << endl;}void play(){cout << m_iAge << endl;cout << "play" << endl;}protected:int m_iAge;};/** * 定义童工类：ChildLabourer * 公有继承工人类和儿童类 */class ChildLabourer:public Worker, public Children{public:ChildLabourer(string name, int age):Worker(name),Children(age){cout << "ChildLabourer" << endl;}~ChildLabourer(){cout << "~ChildLabourer" << endl;}};int main(void){    // 用new关键字实例化童工类对象ChildLabourer *p = new ChildLabourer("alex", 12);    // 调用童工类对象各方法。p->eat();p->work();p->play();delete p;p = NULL;return 0;}