C++ Array containing base/derived class objects [closed] - c++

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I'm trying to put together an assignment here and got stuck on one point. The question is to create Person class with Student derived class. Then overload both << and >> operators. In the end create checking program to create array of 20 Persons and keep loading either Person or Student. At any point we can print what we have by far - Person output is Name char*/Age int/Parents *char[2], Student output is Name char*/Age int/ID int.
My problem is with the array point - I can't figure out how to implement this and right now I'm stuck with:
Array of pointers to person
We choose if its person/student
istream to get the data
Here is main code part:
#include <iostream>
#include <conio.h>
#include "Header.h"
using namespace std;
int main()
{
char choice;
Person* Tablica[20];
Person* temp;
int i = 0;
while (1)
{
cout << "choices:" << endl;
cout << "(p)erson, (s)tudent, s(h)ow, (e)nd" << endl;
choice = _getch();
if (choice == 'h' || choice == 'H'){
for (int n = 0; n < i; n++){
cout << *Tablica[n] << endl;
}
}
if (choice == 'e' || choice == 'E'){ break; }
if (choice == 'p' || choice == 'P'){
temp = new Person;
cin >> *temp;
Tablica[i] = temp;
cout << *Tablica[i] << endl;
i++;
}
if (choice == 'S' || choice == 's'){
temp = new Student;
cin >> *temp;
Tablica[i] = temp;
cout << *Tablica[i] << endl;
i++;
}
}
system("PAUSE");
return 0;
}
I'm able to load first person/student and then code breaks without error.
So what I'm asking here is, could you look at the code and perhaps point me in the right direction?
Disclaimer: We have to use array, no vectors etc. Yes, conio.h is there as well and it has to stay... Obviously I'm beginner.
Person:
#include <iostream>
class Person
{
public:
Person();
Person(const Person&);
Person(char* n, int a, char* Parent1, char* Parent2);
char* getName();
int getAge();
char* getDad();
char* getMum();
virtual ~Person();
virtual Person operator=(const Person &);
virtual Person operator+(const Person &);
virtual Person operator+=(Person &);
virtual void write(std::ostream&);
virtual void read(std::istream&);
friend std::istream& operator>>(std::istream&, Person &);
friend std::ostream& operator<<(std::ostream&, Person &);
protected:
char* name;
int age;
char* ParentName[2];
};
class Student : public Person
{
public:
Student();
Student(const Student&);
Student(char* name, int age, int id);
virtual ~Student();
int ident();
Student operator=(const Student &);
Student operator+(const Student &);
Student operator+=(Student &);
virtual void write(std::ostream&);
virtual void read(std::istream&);
friend std::istream& operator>>(std::istream&, Student &);
friend std::ostream& operator<<(std::ostream&, Student &);
private:
int ID;
};
Class
#include "Header.h"
Person::Person(){
name = 0;
age = 0;
ParentName[0] = 0;
ParentName[1] = 0;
}
Person::Person(const Person & other)
{
name = other.name;
age = other.age;
ParentName[0] = other.ParentName[0];
ParentName[1] = other.ParentName[1];
}
Person::Person(char* n, int a, char* Parent1, char* Parent2){
name = n;
age = a;
ParentName[0] = Parent1;
ParentName[1] = Parent2;
}
Person::~Person(){}
char* Person::getName(){ return name; }
int Person::getAge(){ return age; }
char* Person::getDad(){ return ParentName[0]; }
char* Person::getMum(){ return ParentName[1]; }
Person Person::operator=(const Person & other){
name = other.name;
age = other.age;
ParentName[0] = other.ParentName[0];
ParentName[1] = other.ParentName[1];
return *this;
}
Person Person::operator+=(Person & other){
int i;
i = strlen(name) + strlen(other.name) + 4;
char * temp = new char[i];
strcpy_s(temp, i, name);
strcat_s(temp, i, " - ");
strcat_s(temp, i, other.name);
name = temp;
Person wynik(name, age, ParentName[0], ParentName[1]);
return wynik;
}
Person Person::operator+(const Person & other){
int i;
i = strlen(name) + strlen(other.name) + 4;
char * temp = new char[i];
strcpy_s(temp, i, name);
strcat_s(temp, i, " - ");
strcat_s(temp, i, other.name);
Person wynik(temp, age, ParentName[0], ParentName[1]);
return *this;
}
void Person::write(std::ostream& os)
{
os << "Osoba: name = " << this->getName() << ", wiek = " << this->getAge() << ", rodzice: " << this->getDad() << ", " << this->getMum();
}
std::ostream& operator<<(std::ostream& os, Person & other){
other.write(os);
return os;
}
void Person::read(std::istream& is)
{
char* name;
name = new char;
std::cout << "name: " << std::endl;
is >> name;
std::cout << "age: " << std::endl;
int age;
is >> age;
std::cout << "dad: " << std::endl;
char* dad;
dad = new char;
is >> dad;
std::cout << "mum: " << std::endl;
char* mum;
mum = new char;
is >> mum;
Person p(name, age, dad, mum);
*this = p;
}
std::istream & operator>>(std::istream & is, Person & os){
os.read(is);
return is;
}
Student::Student() : Person(){}
Student::Student(const Student& student) : Person(student){
ID = student.ID;
}
Student::Student(char* name, int age, int id) : Person(name, age, 0, 0){
ID = id;
}
Student::~Student(){}
Student Student::operator=(const Student & student){
Person::operator=(static_cast<Person const&>(student));
ID = student.ID;
return *this;
}
Student Student::operator+=(Student & student){
Student wynik(*this);
wynik.Person::operator=(wynik.Person::operator+=(student));
return wynik;
}
Student Student::operator+(const Student& student)
{
Person::operator+(static_cast<Person const&>(student));
return *this;
}
void Student::write(std::ostream& os)
{
os << "Student: name = " << this->getName() << ", age = " << this->getAge() << ", legitymacja: " << this->ident() << std::endl;
}
int Student::ident(){ return ID; }
std::ostream& operator<<(std::ostream& os, Student & other){
other.write(os);
return os;
}
void Student::read(std::istream& is)
{
char* name;
name = new char[20];
std::cout << "name: " << std::endl;
is >> name;
std::cout << "age: " << std::endl;
int age;
is >> age;
std::cout << "ID: " << std::endl;
int id;
is >> id;
Student s(name, age, id);
*this = s;
}
std::istream & operator>>(std::istream & is, Student & st){
st.read(is);
return is;
}

Answer 1

Does this compile?
Table[i] = *temp;
Table is an array of pointers to Person
temp is a pointer to Person
You are trying to put an object into an array that holds pointers. Dereferencing *temp gives you an object - you need a pointer to an object, so don't dereference it there. I would expect the compiler to complain about that... does it?
Also, check your second if statement - it says (choice == 'S' || choice == 'p'), which is probably not what you meant. Both if blocks will execute if choice == 'p'...
And in Person::read() you've only allocated a single character for name. That is likely to end badly...