Segmentation fault in header file - class

Question

I have defined a Parent.h file, having Parent class with following data members:-
#pragma once
#include <string>
using namespace std;
class Person
{
private:
string id;
string name;
string email;
int contact_number;
string address;
public:
Person();
~Person();
void set_id(string);
void set_name(string);
void set_email(string);
void set_contact_number(int);
void set_address(string);
string get_id();
string get_name();
string get_email();
int get_contact_number();
string get_address();
};
Person::Person()
{
this->id = "";
this->name = "";
this->email = "";
this->contact_number = 0;
this->address = "";
}
void Person::set_id(string id)
{
this->id =id;
}
I have defined the rest of the functions(setters and getters) likewise in Parent.h file.
After that I am making a child class in Student.h header file, this Student class will publicly inherit the Parent class
#pragma once
#include"Courses.h" //course is aggregating to a student
#include"AcademicRecord.h"
#include "Person.h"
#include "Department.h"
#include<string>
#include<vector>
using namespace std;
class Student:public Person,public AcademicRecord,public Department
{
private:
string institute_email;
public:
Courses A;//A contains all information about the courses a student has opt for.
Student();
~Student();
//Using polymorphism between methods
void ShowStudentAcademicRecord(); //shows the academic record of current student
void ShowStudentCoursesInfo(); //getting the information for all courses of student
//setter
void set_institute_email(string email);
void setDepartmentID(string);
//getter
string get_institute_email();
};
After that I have a Display.h file having vector of Students as its Data member and using a member function in Display, I am asking user to input data members like ID,Name,Address,... for individual students.
#include "Student.h"
using namespace std;
class Display
{
public:
vector<Student> students;
Display();//default constructor
//setter
void setStudentData();
};
void Display::setStudentData()
{
int size;
cout<<"Enter the number of students: ";
cin>>size;
Student *current; //current Student
for (int i = 0; i < size; i++)
{
current = &students[i];
cout<<"For student "<<i+1<<"\nEnter the following: \n";//For general details
cout<<"ID Name Email Contact_Number Address Institute_Email\n";
string ID,Name,EMail,Address,insti_email;
int contact_number;
cin>>ID>>Name>>EMail>>contact_number>>Address>>insti_email;
current->set_id(ID);
current->set_name(Name);
current->set_email(EMail);
current->set_contact_number(contact_number);
current->set_address(Address);
current->set_institute_email(insti_email);
}
And when I try inserting value insides students by executing main.cpp file.
I get segmentation fault at run-time inside Person class at setter function, where the first setter I have declared inside the class is void set_id(string).
#include "Display.h"
#include<vector>
#include<string>
int main()
{
Display display;
display.setStudentData();
}
Error:-
I tried:-
1.Rechecking the setter function for any error
2.Bring all the classes inside the main.cpp file,instead of header files, but still the error continues.
I expected the program to take the desired input for various data members of student elments of vector students inside Display class.
Instead I got a seg-fault.
Please if anyone can tell me what I have done wrong, or do I have to do malloc somewhere, inside a function?

Answer 1

As Nate Eldredge, has said I should use push_back instead of accessing ith element of students vector in setStudentData() function, as initially during default declaration of a Display class, the students vector is empty. Hence trying to access students[i] in current = &students[i], I am getting segmentation fault.
The appropriate code for Display.h should be then
#include "Student.h"
using namespace std;
class Display
{
public:
vector<Student> students;
Display();//default constructor
//setter
void setStudentData();
};
void Display::setStudentData()
{
int size;
cout<<"Enter the number of students: ";
cin>>size;
total_students += size;
Student *temp =new Student(); //temp Student
for (int i = 0; i < size; i++)
{
cout<<"For student "<<i+1<<"\nEnter the following: \n";//For general details
cout<<"ID Name Email Contact_Number Address Faculty_Type Faculty_Description\n";
string ID,Name,EMail,Address,insti_email;
int contact_number;
cin>>ID>>Name>>EMail>>contact_number>>Address>>insti_email;
temp->set_id(ID);
temp->set_name(Name);
temp->set_email(EMail);
temp->set_contact_number(contact_number);
temp->set_address(Address);
temp->set_institute_email(insti_email);
cout<<"Enter the Course Details: \n";//For Course Details
int size_course;
cout<<"Enter the number of courses: ";
cin>>size_course;
cout<<"Enter the following for each course: \n";
cout<<"Course_Name Marks Attendance Percentage \n";
string name;
int marks;
float attendance;
for (int i = 0; i < size_course; i++)
{
cin>>name>>marks>>attendance;
temp->A.set_courses_enrolled(name);
temp->A.set_course_wise_marks(marks);
temp->A.set_coursewise_attendance_percentage(attendance);
}
cout<<"Enter the Academic Record Details: \n";//For Academic Record Details
string program_name; int admission_no, enroll_no, begin_year, end_year, credits; float CGPA;
cout<<"Enter Program_name, admission_no enroll_no begin_year end_year credits CGPA";
cin>>program_name>>admission_no>>enroll_no>>begin_year>>end_year>>credits>>CGPA;
setStudentAcademicRecord(temp,i,program_name,admission_no,enroll_no,begin_year,end_year,credits,CGPA); //passing temp pointer in this one
students.push_back(*temp); //adding a new student in students vector
}