第三次上机报告

学号：姓名：班级：软件工程141继承与派生(4学时)一、实验目的1．学习定义和使用类的继承关系，定义派生类。2．熟悉不同继承方式下对基类成员的访问控制。3．学习利用虚基类解决二义性问题。二、实验任务1．定义一个基类Animal，有私有整型成员变量age，构造其派生类dog，在其成员函数SetAge(intn)中直接给age赋值，看看会有什么问题，把age改为公有成员变量，还会有问题吗?编程试试看。2．定义一个基类BaseClass，有整型成员变量Number，构造其派生类DerivedClass，观察构造函数和析构函数的执行情况。3.分析并调试以下程序运行结果，并和实际运行结果相对照。#include<iostream>usingnamespacestd;classBase{ intx;public: Base(inti) { x=i; cout<<"ConstuctorofBase"<<endl; } ~Base(){ cout<<"DestuctorofBase"<<endl; } voidshow() { cout<<"x="<<x<<endl; }};classDerived:publicBase{ Based;public: Derived(inti):Base(i),d(i)};intmain(){ Derivedobj(5); obj.show(); return0;}4．定义一个车(vehicle)基类，具有MaxSpeed、Weight等成员变量，Run、Stop等成员函数，由此派生出自行车(bicycle)类、汽车(motorcar)类。自行车(bicycle)类有高度(Height)等属性，汽车(motorcar)类有座位数(SeatNum)等属性。从bicycle和motorcar派生出摩托车(motorcycle)类。在继承过程中，注意把vehicle设置为虚基类。如果不把vehicle设置为虚基类，会有什么问题?编程试试看。5．设计people(人员)类，考虑到通用性，抽象出所有类型人员都具有的属性：number(编号)、sex(性别)、birthday(出生日期)、id(身份证号)等等。派生出student(学生)类，添加属性：班号charclassNO[7]；从people类派生出teacher(教师)类，添加属性：职务charprincipalship[11]、部门chardepartmentE21]。从student类中派生出graduate(研究生)类，添加属性：专业charsubject[21]、导师teacheradviser；从graduate类和teacher类派生出TA(助教生)类，注意虚基类的使用。重载相应的成员函数，测试这些类。三、实验步骤1.若将age设置为私有成员，在其派生类中直接给其赋值，会出现错误提示：将age设置为公有成员时，能正常运行代码：#include<iostream>usingnamespacestd;classAnimal{public:intage;};classdog:publicAnimal{public:intsetAge(intn)}运行结果为：2.执行情况为：（1）基类BaseClass的构造函数；（2）派生类DerivedClass的构造函数；（3）派生类DerivedClass的析取函数；（4）基类BaseClass的析取函数；代码：#include<iostream>usingnamespacestd;classBaseClass{public:BaseClass(){Number=90;cout<<"constructorofBaseClass!"<<endl;}~BaseClass(){cout<<"destructorofBaseClass!"<<endl;}private:intNumber;};classDerivedClass:publicBaseClass{public:DerivedClass(){cout<<"constrctorofDerivedClass!"<<endl;}~DerivedClass(){ cout<<"destructorofDerivedClass!"<<endl;}};intmain(){return0;}执行结果：3.分析：（1）执行Base的构造函数；（2）执行Derived的对象obj的Base类构造函数，并将obj(5)中参数5赋值给X及Derived类构造函数；（3）执行Derived类的对象obj的Derived的析取函数、在执行Derived类的obj的Base析取函数，最后执行与第一步相对应的Base的析取函数；执行结果：4.虚基类：使得在继承间接共同基类时只保留一份成员。若不使用虚基类，在最终的派生类中会保留该间接共同基类数据成员的多份同名成员。代码：#include<iostream>usingnamespacestd;classvehicle{public: vehicle(floatm,floatw) { MaxSpeed=m;Weight=w; } ~vehicle(){} voidrun() { cout<<"runningofvehicle!"<<endl; } voidstop() { cout<<"stoppingofvehicle!"<<endl; }floatMaxSpeed; floatWeight;};classbicycle:virtualpublicvehicle{public: bicycle(floatm,floatw,floath):vehicle(m,w) { Height=h; } ~bicycle(){} { SeatNum=s; } ~motorcar(){} intSeatNum;};classmotorcycle:publicbicycle,publicmotorcar{public: motorcycle(floatm,floatw,floath,ints):vehicle(m,w),bicycle(m,w,h),motorcar(m,w,s){} ~motorcycle(){} voiddisplay() {cout<<"MaxSpeed="<<MaxSpeed<<endl; cout<<"Weight="<<Weight<<endl; cout<<"Height="<<Height<<endl; cout<<"SeatNum="<<SeatNum<<endl; }};voidmain(){ floatm,w,h; ints; cout<<"pleaseinput\nMaxSpeed="; cin>>m; cout<<"Weight="; cin>>w; cout<<"Height="; cin>>h; cout<<"SeatNum="; cin>>s; motorcyclemoc(m,w,h,s); moc.display();}运行结果：5.代码：#include<iostream>#include<string> }; ~People(){}protected: stringnumber; stringsex; stringbirthday; stringid;};classStudent:virtualpublicPeople{public: Student(stringn,strings,stringb,stringi,stringc):People(n,s,b,i) { classNo=c; } ~Student(){}protected:stringclassNo;};classTeacher:virtualpublicPeople{public: Teacher(stringn,strings,stringb,stringi,stringp,stringd):People(n,s,b,i) { principalship=p; department=d; } ~Teacher(){}protected: stringprincipalship;//职务 stringdepartment;//部门};classGraduate:publicStudent } ~Graduate(){}protected: stringsubject;//专业 stringteacher_adviser;//导师};classTA:publicGraduate,publicTeacher{public: TA(stringn,strings,stringb,stringi,stringc,stringsu,stringt,stringp,stringd):People(n,s,b,i),Graduate(n,s,b,i,c,su,t),Teacher(n,s,b,i,p,d) {} ~TA(){} voiddisplay() { cout<<"编号:"<<number<<endl; cout<<"性别:"<<sex<<endl; cout<<"生日:"<<birthday<<endl; cout<<"身份证号:"<<id<<endl; cout<<"班级:"<<classNo<<endl; cout<<"专业:"<<subject<<endl; cout<<"导师:"<<teacher_adviser<<endl; cout<<"导师职务:"<<principalship<<endl; cout<<"导师部门:"<<department<<endl; }};voidmain(){ stringn,s,b,i,c,su,t,p,d; cout<<"请输入编号："<<endl;cin>>n; cout<<"请输入性别："<<endl;cin>>s; cout<<"请输入生日："<<endl;cin>>b; cout<<"请输入身份证号："<<endl;cin>>i; cout<<"请输入班级："<<endl;cin>>c; cout<<"请输入专业："<<endl;cin>>su; cout<<"请输入导师："<<endl;cin>>t; cou