- 1. Inheritance Introduction
- 2. Inheritance: Access Control
- 5. Multiple Inheritance
- 7. Student Playground
1. Inheritance Introduction
main.hpp:
/*The header file for inheritance.*/
#include<iostream>
#include<string>
using namespace std;
//The base class
class Student
{
private:
int id;
public:
void setId(int idIn);
int getId();
Student();
};
Student::Student()
{
id = 000000000;
}
void Student::setId(int idIn)
{
id = idIn;
}
int Student::getId()
{
return id;
}
//The derived class with Student as base class
class GradStudent : public Student
{
private:
string degree;
public:
GradStudent();
void setDegree(string degreeIn);
string getDegree();
};
GradStudent::GradStudent()
{
degree = "undelcared";
}
void GradStudent::setDegree(string degreeIn)
{
degree = degreeIn;
}
string GradStudent::getDegree()
{
return degree;
}
main.cpp:
/*Goal: study a simple example if inheritance.
*/
#include"main.hpp"
int main()
{
//Create an instance of the derived class,
//GradStudent
GradStudent gs1;
//Set the id of the grad student
//using the function in the base class
gs1.setId(123456789);
//Set the degree of the grad student
//using the function in the derived class
gs1.setDegree("BSEE");
cout<<gs1.getId()<<" "<<gs1.getDegree();
return 0;
}
2. Inheritance: Access Control
There are three types of access control: public, private, and protected.三种类的继承方式：
- Public Inheritance means all public members of the base class are accessible to the derived class 能访问基类的公有成员变量
- Private Inheritance means all members of the base class are private to the derived class 不能访问基类的成员变量
- Protected Inheritance means all members of the base class are protected to the derived class.
上面的示例代码中，因为是public继承，所以子类能直接使用父类的公有函数，但是下面的是private继承，所以不能使用父类的getId()了。
main.hpp:
/*The header file for inheritance.*/
#include<iostream>
#include<string>
using namespace std;
//The base class
class Student
{
private:
int id;
public:
void setId(int idIn);
int getId();
Student();
void setId();
};
Student::Student()
{
id = 000000000;
}
void Student::setId(int idIn)
{
id = idIn;
}
int Student::getId()
{
return id;
}
//The derived class with Student as base class
class GradStudent : private Student
{
private:
string degree;
public:
GradStudent();
void setDegree(string degreeIn);
string getDegree();
void setStudentId(int idIn);
int getStudentId();
};
GradStudent::GradStudent()
{
degree = "undelcared";
}
int GradStudent::getStudentId()
{
return Student::getId();
}
void GradStudent::setStudentId(int idIn)
{
Student::setId(idIn);
}
void GradStudent::setDegree(string degreeIn)
{
degree = degreeIn;
}
string GradStudent::getDegree()
{
return degree;
}
main.cpp:
/*Goal: study a simple example if inheritance.
*/
#include"main.hpp"
int main()
{
//Create an instance of the derived class,
//GradStudent
GradStudent gs1;
//Set the id of the grad student
//using the function in the base class
gs1.setStudentId(123456789);
//Set the degree of the grad student
//using the function in the derived class
gs1.setDegree("BSEE");
cout<<gs1.getStudentId()<<" "<<gs1.getDegree();
return 0;
}
5. Multiple Inheritance
C++能多重继承，下面的代码中，从父类Staff和GradStudent中，继承得到了TA子类：
//header file for main.cpp
#include<iostream>
#include<string>
using namespace std;
class Staff
{
private:
string title;
public:
Staff();
void setTitle(string input);
string getTitle();
};
Staff::Staff()
{
title = "NA";
}
void Staff::setTitle(string input)
{
title = input;
}
string Staff::getTitle()
{
return title;
}
class GradStudent
{
private:
int studentId;
public:
GradStudent();
void setId(int input);
int getId();
};
GradStudent::GradStudent()
{
studentId = 000000;
}
void GradStudent::setId(int input)
{
studentId = input;
}
int GradStudent::getId()
{
return studentId;
}
class TA: public Staff, public GradStudent
{
private:
string supervisor;
public:
TA();
void setSupervisor(string input);
string getSupervisor();
};
TA::TA()
{
supervisor = "NA";
}
void TA::setSupervisor(string input)
{
supervisor = input;
}
string TA::getSupervisor()
{
return supervisor;
}
/*Goal: understand multiple inheritance*/
#include "main.hpp"
int main()
{
TA t1;
t1.setSupervisor("Dr. Caohuu");
t1.setId(55555);
t1.setTitle("Adjunct Prof.");
cout<<t1.getSupervisor()<<" "<<t1.getId()<<" "<<t1.getTitle();
return 0;
}
7. Student Playground
- Compile the code and create an execuable file called main.out
g++ main.cpp -o main.out
- Execute the executable file using input.txt as the input
./main.out input.txt