I am writing a university management system and I have total of ten classes.As we know we establish polymorhism between classes when we use virtual function in base class and then we inherit derived classes from the base class and the virtual function is overriden in derived classes but here I am facing a problem which I have never faced as I have implemented polymorphism many times in c++ but the now it gives error when I write this statement and the error is at new keyword.It can be seen in the display class
//Using Polymorphism
Department* department=new Faculties();
I am unable to establish polymorphism between these department and the faculties class.Similarly there is an employee class which is derived from department and same error is there I am very much confused as I am still a begginer in OOP. Department Class
#pragma once
#include"Accounts.h"
#include"Faculties.h"
#include"Employee.h"
#include<iostream>
#include<vector>
using namespace std;
#include<string>
class Department
{
public:
Department()=default;
~Department()=default;
//Declaring the methods
//Setters
void setDepartmentID(int);
void setDepartmentStrength(int);
void setHODName(string);
//Inheriting
virtual void setName(string);
virtual void set_id(int);
virtual void set_address(string);
virtual void setEmail(string);
//Defining getters
virtual string getName(int);
virtual int get_id(int);
virtual string get_address(int);
virtual string getEmail(int);
//for calculating payments
virtual void set_payments(float, string, float)=0;
virtual void showPaymentDetails(int);
//getters
int getDepartmentStrength();
private:
vector<string> departmentName;
vector<string> departmentHOD;
vector<int> departmentID;
vector<int> departmentStrength;
//Declaring an array to enter the department faculties
};
Department::Department()
{
}
Department::~Department()
{
}
void Department::setDepartmentID(int id)
{
departmentID.push_back(id);
}
void Department::setName(string name)
{
departmentName.push_back(name);
}
void Department::setDepartmentStrength(int strength)
{
departmentStrength.push_back(strength);
}
void Department::setHODName(string name)
{
departmentHOD.push_back(name);
}
int Department::getDepartmentStrength()
{
static int sum = 0;
for (size_t i = 0; i < departmentStrength.size(); i++)
{
sum = sum + departmentStrength[i];
}
return sum;
}
Faculties class
#pragma once
#include"Accounts.h"
#include"Department.h"
#include<iostream>
#include<string>
#include<vector>
using namespace std;
class Faculties:public Department
{
public:
Faculties()=default;
~Faculties()=default;
//////////////////////////////////Using Polymorphism///////////////////////////////////
//Setters
void setName(string) override;
void set_id(int) override;
void set_address(string) override;
void setEmail(string) override;
void set_payments(float, string, float);
//Getters
string getName(int) override;
int get_id(int) override;
string getEmail(int) override;
string get_address(int) override;
//for showing payments
void showPaymentDetails(int) override;
private:
vector<int> faculty_id;
vector<string> faculty_name;
vector<string> faculty_email;
vector<string> faculty_address;
vector<string> faculty_type;
vector<string> faculty_description;
Accounts accounts;
};
Faculties::Faculties()
{
}
Faculties::~Faculties()
{
}
void Faculties::set_id(int id)
{
this->faculty_id.push_back(id);
}
void Faculties::setEmail(string email)
{
this->faculty_email.push_back(email);
}
void Faculties::setName(string name)
{
this->faculty_name.push_back(name);
}
void Faculties::set_address(string saddress)
{
this->faculty_address.push_back(saddress);
}
string Faculties::getName(int index)
{
return this->faculty_name[index];
}
int Faculties::get_id(int index)
{
return this->faculty_id[index];
}
string Faculties::getEmail(int index)
{
return this->faculty_email[index];
}
string Faculties::get_address(int index)
{
return this->faculty_address[index];
}
void Faculties::set_payments(float decidedSalary, string payment_method, float total_working_hours)
{
//Using composition
accounts.set_decided_salary(decidedSalary);
accounts.set_payment_method(payment_method);
accounts.set_total_working_hours(total_working_hours);
}
void Faculties::showPaymentDetails(int index)
{
cout << "\nThe decided salaray of faculty with name " << faculty_name[index] << " is " <<
accounts.get_decided_salary(index);
cout << "\nThe payment method of faculty with name " << faculty_name[index] << " is " <<
accounts.get_payment_method(index);
cout << "\nThe deducted salary of faculty with name " << faculty_name[index] << " is " <<
accounts.get_deducted_salary(index);
cout << "\nThe paid salary of faculty with name " << faculty_name[index] << " is " <<
accounts.get_paid_salary(index);
cout << "\nThe bonus salary paid of faculty with name " << faculty_name[index] << " is " <<
accounts.get_bonus_salary(index);
}
Display class here it gives error and same in source.cpp
#pragma once
#include"Department.h"
#include"Student.h"
#include"Courses.h"
#include"SubCampuses.h"
#include"Faculties.h"
#include"Employee.h"
#include<iostream>
#include<vector>
#include<string>
using namespace std;
class Display
{
public:
Display()=default;
~Display()=default;
void setStudentsData(string, int, string)
{
}
void setStudentsData(string name, int id, string address, string email, int departmentID, int departmentStrength, string HODname);
void setStudentsAcademicRecord(float marks, char grades, float attandancePercentage, float CGPA);
void setStudentCourseInfo(Courses courses, string coursesEnrolled, float courseWiseAttandancePercentage, float courseWiseMarks);
//Setting the faculties of students
void setFacultiesInfo(string name,int id,string address,string email, float decidedSalary, string payment_method, float total_working_hours);
//setting the employees info
//void setEmployeesInfo(string name, int id, string address, string email, float decidedSalary, string payment_method, float total_working_hours);
void ShowStudentCoursesInfo();
void ShowStudentRecord(int);
void ShowFacultiesDetails(int);
//void ShowEmployeesDetails(int);
private:
//Using Inheritance
Student *student;
Courses courses;
Faculties faculties;
//Using Polymorphism
Department* department=new Faculties(); ///////////////////Here is the error ////////////////////////
};
Display::Display()
{
}
Display::~Display()
{
}
void Display::setStudentsAcademicRecord(float marks, char grades, float attandancePercentage, float CGPA)
{
student->set_student_marks(marks);
student->set_student_grades(grades);
student->set_Attandance_percentage(attandancePercentage);
student->set_GCPA(CGPA);
}
void Display::setStudentsData(string name, int id, string address, string email,int departmentID,int departmentStrength,string HODname)
{
student->setName(name);
student->set_id(id);
student->set_address(address);
student->setEmail(email);
}
void Display::ShowStudentRecord(int id)
{
cout<<"\nThe name of student is equal to "<<student->getName(id);
cout << "\nThe Id of student is equal to " << student->get_id(id);
cout << "\nThe Email of student is equal to " << student->getEmail(id);
cout << "\nThe Adress of student is equal to " << student->get_address(id);
//Now showing the student academic records
student->ShowStudentAcademicRecord(id);
}
void Display::setStudentCourseInfo(Courses courses, string coursesEnrolled, float courseWiseAttandancePercentage, float courseWiseMarks)
{
courses.set_courses_enrolled(coursesEnrolled);
courses.set_coursewise_attendance_percentage(courseWiseAttandancePercentage);
courses.set_course_wise_marks(courseWiseMarks);
}
void Display::ShowStudentCoursesInfo()
{
//Passing the courses object to the courses info
student->ShowStudentCoursesInfo(courses);
}
void Display::setFacultiesInfo(string name, int id, string address, string email, float decidedSalary, string payment_method, float total_working_hours)
{
department->setName(name);
department->set_id(id);
department->set_address(address);
department->setEmail(email);
department->set_payments(decidedSalary, payment_method, total_working_hours);
}
void Display::ShowFacultiesDetails(int id)
{
cout<<"\nThe id of department faculty is "<<department->get_id(id);
cout << "\nThe Name of department faculty is " << department->getName(id);
cout << "\nThe Email of department faculty is " << department->getEmail(id);
cout << "\nThe Address of department faculty is " << department->get_address(id);
cout << "\nThe Department faculty strength is " << department->getDepartmentStrength();
}
The screen shot of the error is below The error picture The complete program is at the following link https://github.com/Muhammad-Bilal-7896/Univeristy-Management-System
