Question

For each line of text:

-Get first name
-Get last name
-Get Student Number

(There will be an unknown amount of lines, each looking the same in format.)
Format:

First Last 111111111
First Last 111111112
...

I want to put each piece of each student into its own struct. I’ve set up the struct as follows:

struct Student{  
    string lastName;
    string firstName;
    string stdNumber;
    double assgn1;//doubles will be used later in prog.
    double assign2;
    double assign3;
    double assign4;
    double midTerm;
    double finalGrade;
};

My file input function is as follows:

int getFileInfo()
{       
    int failed=0;
    ifstream fin;   
    string fileName;    
    vector<Student> students;

    Student s;                  // A place to store data of one student
    cout<<"Please enter the filename of the student grades (ex. filename_1.txt)."<<endl;
    do{                                 
        if(failed>=1)                           
            cout<<"Please enter a correct filename."<<endl; 
        cin>>fileName;                              
        fin.open(fileName.c_str());// Open the file     
        failed++;                                           
    }while(!fin.good());                                        
    while (fin >> s.firstName >> s.lastName >> s.stdNumber)
        students.push_back(s);                      
    fin.close();                            
    return 0;                                   
}  

In the file input, I make a vector, but I am unsure how to access each individual part of it, or the student, s, because it seems that it only makes one student. I was told that each line of the file is split and inputted into the students vector, but I don’t know how to extract that information. How do I get each student out of the students vector and into its own struct so I can use each student as its own struct?
So in the end, I would want to be able to output:

Student1: First Last 111111111
Student2: First Last 111111112
However More students are in the file

Thanks in advance for the help!!

@Loki
I changed the loop so loop != end and I still get the same problem. Here is my code:

int getFileInfo()
{
int failed=0;
ifstream fin;
string fileName;
vector<Student> students;// A place to store the list of students
vector<Student>::iterator loop = students.begin();
   vector<Student>::iterator end  = students.end();

Student s;                  // A place to store data of one student
cout<<"Please enter the filename of the student grades (ex. filename_1.txt)."<<endl;
do{
if(failed>=1)
    cout<<"Please enter a correct filename."<<endl;
    cin>>fileName;
    fin.open(fileName.c_str());// Open the file
    failed++;
}while(!fin.good());

 while (fin >> s.firstName >> s.lastName >> s.stdNumber){
    cout<<"Reading "<<s.firstName<<" "<<s.lastName<<" "<<s.stdNumber<<endl;
    students.push_back(s);
}
fin.close();

    for(loop;loop!=end;++loop)
    cout<<loop->firstName<<" "<<loop->lastName<<" "<<loop->stdNumber<<endl;

return 0;
}

Again, Visual studio is saying vector iterators incompatible,
Pointing to “C:\Program Files(x86)\Microsoft Visual Studio 10.0\vc\include\vector”

Answer 1

In the file input, I make a vector, but I am unsure how to access each individual part of it.

You can access individual elements via the operator[]

students[0].firstName;  // get the first name.

std::cout << students[1].firstName; // prints out the first name.

You can use an index from 0 -> size().

size_t  size = students.size();  // number of students in the vector.

students[size].firstName; // This is wrong. You expression in
                          // [] must be less than size as the elements are
                          // numbered from 0 to size() -1.

because it seems that it only makes one student.

You are creating only one student ‘s’ (As a side not pick a better name). But when you call push_back() you are copying this student object into the vector. So the vector gets a copy of ‘s’ that it stores. Then each time through the loop you overwrite the old values in ‘s’ with new values retrieved from the file.

I was told that each line of the file is split and inputted into the students vector, but I don’t know how to extract that information.

As noted above each element can be reached individually using the operator[]

Alternatively you can use iterators to get a range. of students.

 std::vector<Student>::iterator loop = students.begin();
 std::vector<Student>::iterator end  = students.end();

You can access an element by de-referencing loop and move to the next student by incrementing loop.

 std::cout << loop->firstName;   // prints out student[0]
 ++loop;                         // Increment loop now it points at student 1
 std::cout << loop->firstName;   // prints out student[1]
 ++loop;                         // Increment loop now it points at student 2
 // etc

If loop == end then you have moved past all the students.

How do I get each student out of the students vector and into its own struct so I can use each student as its own struct?

The students are in the vector already in structs. you can use them directly as you would a struct outside. But if you want to copy them out you can do this:

Student   tmp = students[0]; // copies student 0 into tmp.

I would want to be able to output:

Use std::cout to output stuff to the standard output. Or create an object of type std::ofstream to output to a file:

std::cout << tmp.lastName  << " " 
          << tmp.firstName << " "
          << tmp.stdNumber << "\n";

std::ofstream  file("plop1.txt");
file      << tmp.lastName  << " " 
          << tmp.firstName << " "
          << tmp.stdNumber << "\n";