My program is not correctly outputting the amount of students in my struct

Question

i am making a program which is supposed to collect input from the user by asking for id, name, units attempted, units earned and the gpa of a student and store that into a struct. Currently, when i input more than one student into the struct, it only outputs the last student in the array. What can i do to fix this?

Here is my code

#include <iostream>
#include <string>
#include <iomanip>

using namespace std;

struct Student {
string ID;      //an 8-digit student ID
string name;        //name of the student
unsigned unitsAttempted;//number of units attempted by the student
unsigned unitsEarned;   //number of units earned by the student
double gpa;     //the grade point average for the student
};


int main()
{
  Student students[10];//array for 10 Student Structs
  
  char answer = 'y';
  int number = 0;

  while ((answer == 'y') || (answer == 'Y')) {
   //prompt the user to enter the data
  {
    answer = ' ';
    int i = 0;

    cout << "Enter the students ID: \n" ;
    getline(cin, students[i].ID);

    cout << "\nEnter the name:\n";
    getline(cin, students[i].name);

    cout << "\nEnter the units attempted:\n";
    cin >> students[i].unitsAttempted;
    cin.ignore();

    cout << "\nEnter the units earned:\n";
    cin >> students[i].unitsEarned;
    cin.ignore();

    cout << "\nEnter the GPA: \n";
    cin >> students[i].gpa;
    cin.ignore();

    cout << "\nWould you like to add another student? y or n\n";  
    cin >> answer;
    cin.ignore();

    i++;
    number++;
  }
  }
  

  cout << left << setw(10) << "ID " << setw(20) <<"Name" << setw(20) <<"Units Attempted" << setw(20) <<"Units Earned" << setw(10) <<"GPA";
  cout << "\n===============================================================\n";

    for (int i = 0; i < number; i++)//display the students
    {
      cout << left << setw(10) << students[i].ID << setw(20) << students[i].name << setw(20) <<students[i].unitsAttempted << setw(20) <<students[i].unitsEarned << setw(10) <<students[i].gpa << endl << endl;

    }

  return 0;
}

Im still learning so please go easy on me, thanks.

Glad to hear that you're still learning, so the next thing for you to learn is how to use your debugger to run your program one line at a time, inspect the values of all variables, and see exactly what your program is doing. Knowing how to effectively use a debugger is a required skill for every C++ developer, no exceptions. With your debugger's help you can quickly figure out the bugs in your code without asking anyone else for help, good luck! — Sam Varshavchik, Sep 18 '20 at 02:20
Never heard of it. Seem to be some web-based development tool. You can't effectively learn C++ like this. You need both [a good C++ textbook](https://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list), as well as a modern C++ compiler with a debugger. — Sam Varshavchik, Sep 18 '20 at 02:22
gcc on Linux, of course. gdb as a debugger. Pretty hard debugger to learn, but once you do, it's invaluable. — Sam Varshavchik, Sep 18 '20 at 02:27

score 2 · Accepted Answer · answered Sep 18 '20 at 02:21

Currently, when i input more than one student into the struct, it only outputs the last student in the array.

It looks most likely that the scope of your i is incorrect:

    int i = 0;   //<-- this should be declared outside the `while` loop

As it stands, your i is scoped inside while loop, so it will be reset every time the while loop is entered. In other word, that i never increased.

My program is not correctly outputting the amount of students in my struct

1 Answers1