// student.cpp - Script 9.7
#include <iostream>
#include <string>
// Declare the Person class.
class Person {
public:
Person(std::string theName);
void introduce();
protected:
std::string name;
};
// Declare the Teacher class.
// Teacher inherits Person.
class Teacher: public Person {
public:
Teacher(std::string theName, std::string theClass);
void teach();
void introduce();
protected:
std::string clazz;
};
// Declare the Student class.
// Student inherits Person.
class Student: public Person {
public:
Student(std::string theName, std::string theClass);
void attendClass();
void introduce();
protected:
std::string clazz;
};
// Declare the TeachingStudent class.
// TeachingStudent inherits both Student and Teacher.
class TeachingStudent : public Student, public Teacher {
public:
// Constructor.
TeachingStudent(
std::string theName,
std::string classTeaching,
std::string classAttending);
void introduce();
};
// Define the methods.
Person::Person(std::string theName) {
name = theName;
}
void Person::introduce() {
std::cout << "Hi I'm " << name << "\n";
}
Teacher::Teacher(std::string theName, std::string theClass)
: Person(theName) {
clazz = theClass;
}
void Teacher::teach() {
std::cout << name << " teaches ";
std::cout << "'" << clazz << ";.\n";
}
void Teacher::introduce() {
std::cout << "Hi I'm " <<name << ", and I teach '" << clazz << "'\n";
}
Student::Student(std::string theName, std::string theClass): Person(theName) {
clazz = theClass;
}
void Student::attendClass() {
std::cout << name << " attends ";
std::cout << "'" << clazz << "'.\n";
}
void Student::introduce() {
std::cout << "Hi I'm " << name << ", and I study '" << clazz << "'\n";
}
// TeachingStudent's constructor must invoke
// the constructors of all base classes!
TeachingStudent::TeachingStudent(
std::string theName,
std::string classTeaching,
std::string classAttending)
: Teacher(theName, classTeaching),
Student(theName, classAttending)
{
}
void TeachingStudent::introduce() {
// Because TeachingStudent inherits two copies of Person's
// attributes (one from Teacher and one from Student),
// we must tell the compiler which copy to use.
std::cout << "Hi I'm " << Student::name << ". I teach '" << Teacher::clazz << ";, ";
std::cout << "and I study '" << Student::clazz << ";.\n";
}
int main() {
// Create the objects.
Teacher teacher("Jim", "C++ 101");
Student student("Bob", "C++ 101");
TeachingStudent teachingStudent("Mike", "C++ 101", "Advanced C++");
// Make them do things.
teacher.introduce();
teacher.teach();
student.introduce();
student.attendClass();
teachingStudent.introduce();
teachingStudent.teach();
teachingStudent.attendClass();
std::cout << "Press Enter or Return to continue.";
std::cin.get();
return 0;
}
I'm having trouble understanding this code. Can anybody help? In particular having trouble with this part:
TeachingStudent:: TeachingStudent(
std::string theName,
std::string classTeaching,
std::string classAttending)
: Teacher(theName, classTeaching), Student(theName, classAttending)
I don't understand why the parameters are different in the Teacher and Student implementation to the implementation of TeachingStudent i.e (theName, classTeaching) instead of (theName, theClass)- Where the constructors of the base classes are invoked. I also presume Person(theName) isn't called because it's inherited from Student and Teacher?
also
void TeachingStudent::introduce() {
// Because TeachingStudent inherits two copies of Person's
// attributes (one from Teacher and one from Student),
// we must tell the compiler which copy to use.
std::cout << "Hi I'm " << Student::name << ". I teach '" << Teacher::clazz << "', ";
std::cout << "and I study '"<< Student::clazz << "'.\n";
std::cout << "Hi I'm " << Student::name << ". I teach '" << Teacher::clazz << "', ";
std::cout << "and I study '"<< Student::clazz << "'.\n";
I find this confuseing as I'm associateing Student::name with "Bob" from Student student("Bob", "C++101") Teacher::clazz with "C++ 101" from Teacher teacher("Jim", C++ 101"); and Student::clazz with "C++ 101" from Student student("Bob", "C++ 101",
An explanation as to where I'm going wrong would be much appreciated. Thanks in advance.
