Overloading operator =, error in reading string - c++

Question

I am trying to write an overload to the = operator so that it allows you directly assign one student object to another student object. So it will copy all the private data members. Here is what I have so far.
.h
#ifndef PROJECT3HEADER_H
#define PROJECT3HEADER_H
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
class Student
{
public:
Student();
void Setlname(string lname);
void Setfname(string fname);
void SetAverage(float Average);
void SetLettergrade(char lettergrade);
void SetTestScore1(float score1);
void SetTestScore2(float score2);
void SetTestScore3(float score3);
void SetTestScore4(float score4);
void SetTestScore5(float score5);
string Getlname()const;
string Getfname()const;
float GetAverage()const;
char GetLetterGrade()const;
float GetScore1()const;
float GetScore2()const;
float GetScore3()const;
float GetScore4()const;
float GetScore5()const;
//void operator = (const Student & rhs);
Student operator=(const Student &rhs);
private:
string lname,fname;
float testScore[5];
float Average;
char lettergrade;
};
ostream & operator << (ostream &, const Student & pt);
//istream& operator >> (istream& in, Student& pt);
#endif
Studentmem.cpp
#include "Project3Header.h"
#include <iostream>
#include <string>
using namespace std;
Student::Student()
{
lname="";
fname="";
Average=0;
lettergrade=' ';
testScore[0]=0,testScore[1]=0,testScore[2]=0,testScore[3]=0,testScore[4]=0;
}
void Student::Setlname(string lname1){
lname=lname1;
}
void Student::Setfname(string fname1){
fname=fname1;
}
void Student::SetAverage(float average1){
Average=average1;
}
void Student::SetLettergrade(char lettergrade1){
lettergrade=lettergrade1;
}
void Student::SetTestScore1(float score1){
testScore[0]=score1;
}
void Student::SetTestScore2(float score2){
testScore[1]=score2;
}
void Student::SetTestScore3(float score3){
testScore[2]=score3;
}
void Student::SetTestScore4(float score4){
testScore[3]=score4;
}
void Student::SetTestScore5(float score5){
testScore[4]=score5;
}
string Student::Getlname()const {
return lname;
}
string Student::Getfname()const {
return fname;
}
float Student::GetAverage() const{
return Average;
}
char Student::GetLetterGrade()const{
return lettergrade;
}
float Student::GetScore1() const{
return testScore[0];
}
float Student::GetScore2() const{
return testScore[1];
}
float Student::GetScore3() const{
return testScore[2];
}
float Student::GetScore4() const{
return testScore[3];
}
float Student::GetScore5() const{
return testScore[4];
}
Student Student::operator=(const Student &rhs){
lname = rhs.lname;
fname = rhs.fname;
for (int i = 0; i < 5; i++){
testScore[i] = rhs.testScore[i];
}
return *this;
}
std::ostream& operator<<(std::ostream& out, Student const& obj)
{
out << "Lname: " << obj.Getlname() << "\n";
out << "fname: " << obj.Getfname() << "\n";
out << "Average: " << obj.GetAverage() << "\n";
out << "Grade: " << obj.GetLetterGrade() << "\n";
return out;
}
But when I try to use it in the main I get an error... error reading characters of string.
here is a little of my main
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
#include "Project3Header.h"
using namespace std;
//Tyler Smith
void StdInfo(Student array[], int size);
Student * MakeStudentArray(int size);
int main(){
ifstream inData;
int size = 0;
int highsize = 0;
char data[65535];
inData.open("F:\\grade.dat");
if (!inData)
{
cout << "Error opening file.\n";
cout << "Perhaps the file is not where indicated.\n";
return 1;
}
while (inData.getline(data, 65535)) {
size++;
}
inData.close();
cout << size;
Student s1;
Student * ptArr;
ptArr = MakeStudentArray(size);
for (int i = 0; i < size; i++){
ptArr[i]= s1;
}
StdInfo(ptArr,size);
/* for (int i = 0; i < size; i++){
cout << ptArr[i].Getlname() << ptArr[i].Getfname(); //<< ptArr[i].Get() << endl;
}*/
cout << ptArr[2].Getfname();
return 0;
}
Student * MakeStudentArray(int size)
{
return new Student[size];
}
void StdInfo(Student array[], int size){
ifstream in;
in.open("F:\\grade.dat");
string fname1,lname1="";
int Score1, Score2, Score3, Score4, Score5=0;
for (int i = 0; i < size; i++) {
in >> lname1;
in >> fname1;
in >> Score1;
in >> Score2;
in >> Score3;
in >> Score4;
in >> Score5;
array[i].Setlname(lname1);
array[i].Setfname(fname1);
array[i].SetTestScore1(Score1);
array[i].SetTestScore2(Score2);
array[i].SetTestScore3(Score3);
array[i].SetTestScore4(Score4);
array[i].SetTestScore5(Score5);
array[i] = array[i + 1];
//for (int j = 0; j < 5; j++) {
//in >> array[i].testScore[j];
//}
}
}
When I try it simply will not work. When I do it in debug mode it stops at the overloading operator and stays "rhs error reading characters of string"

Answer 1

The essense of your problem is not the (unconventional) assignment operator, but the MakeStudentArray function.
I hardcoded the size to 10, rather than reading it from a file, and used
Student * MakeStudentArray(int size)
{
return new Student[size];
}
taking care to call delete [] ptArr; after I was done in main (worrying about exceptions as I did) and all was well.
Your version allocates Students (maybe all over the heap), rather than an array.
If I change the question code you posted in main to
for (int i = 0; i < size; i++){
ptArr[i].operator= (s1);
//^------- you said 0, right?
}
then I get a problem. This is because the for loop assumes the "array" is contiguous, but your function newed an array of points, not an array of Students, so it walks into goodness only knows where when it tries to loop over the "array".
Using my suggestion version should solve the problem, since it allocates an array using new[size] and also makes it easier to delete.
Edit 1:
With the rest on main now posted, perhaps you do keep trying to set ptArr[0] several times in the loop, but then calling StdInfowill try to walk an "array" and will give you the error. If you wish to index into an array, using [] it must be contiguous, so the allocation function, MakeStudentInfo will still be the cause of the problem.
Edit2:
Now there is even more code, look at your StdInfo function. Without the extra details it does this:
for (int i = 0; i < size; i++) {
//...
array[i] = array[i + 1];
}
What are you trying to achieve here? It looks like set the current array[i] to something we haven't got to yet. Once i gets to size i+1 will be off the end of your array.
Removing that line would be a good idea.

Answer 2

The assignment operator should return a reference to the assigned object, not a copy. Also think about using the copy & swap idiom
Student& Student::operator=(const Student &rhs){