Pointer To Char Array (cin.get & cout) - c++

Question

Just to refresh my concept I'm working on parallel arrays. One is used to store integer data and the other one for char data i.e GPA.
The problem compiles like a charm but the result is not correct, it displays the Student IDs correctly but not the GPA.
The simple cin works fine
I don't really know how to use cin.get and cin.getline using pointers.
In function enter I want to get the two-character-long string (plus one terminating null character).
Code listing:
#include <iostream>
#include <cstring>
using namespace std;
void enter(int *ar, char *arr, int size);
void exit(int *a, char *yo, int size);
int main()
{
const int id = 5;
const char grade = 5;
int *student = new int[id];
char *course = new char[grade];
cout << "\n";
enter(student, course, 5);
exit(student, course, 5);
}
void enter(int *ar, char *arr, int size)
{
for(int i = 0; i < size; i ++)
{
cout << "Student ID: " << i+1 << "\n";
cin >> *(ar+i);
cin.ignore();
cout << "Student Grade: " << i+1 << "\n";
cin.get(arr, 3);
}
}
void exit(int *a, char *yo, int size)
{
for(int i = 0; i < size; i ++)
{
cout << "ID And Grade Of Student #" << i+1 << ":";
cout << *(a+i) << "\t" << *(yo+j) << endl;
}
}

Answer 1

You are attempting to use part of the C++ language, but not embrace it entirely. There is no need for you to manage memory (at all) to solve this problem. Additionally, it would be much better to solve it using the standard language features:
struct Info
{
int StudentId;
std::string Grade; // this could easily be stored as an int or a char as well
};
int main()
{
const std::vector<Info>::size_type SIZE_LIMIT = 5;
std::vector<Info> vec(SIZE_LIMIT);
for (std::vector<Info>::size_type i = 0; i < SIZE_LIMIT; ++i)
{
std::cout << "Enter a Student ID: ";
std::cin >> vec[i].StudentId;
std::cout << "Enter a Grade: ";
std::cin >> vec[i].Grade;
}
std::for_each(vec.begin(), vec.end(), [&](const Info& i)
{
std::cout << "Student ID: " << i.StudentId << ", Grade: " << i.Grade << std::endl;
});
return 0;
}
Which can very easily be converted to account for more than 5 (e.g. virtually infinite) by adding an overload for std::istream& operator>>(std::istream&, Info&) and changing the for-loop to a std::copy operation.
If you absolutely want to keep your hands tied behind your back, you should at least make the following changes:
const unsigned int CLASS_SIZE = 5;
const unsigned int GRADE_SIZE = 5;
int student[CLASS_SIZE];
char course[CLASS_SIZE][GRADE_SIZE] = {};
// initialize course grades to empty strings, if you don't use the = {} above
for (unsigned int i = 0; i < CLASS_SIZE; ++i)
{
memset(course[i], 0, GRADE_SIZE);
}
// ...
// use your constants for your sizes
enter(student, course, CLASS_SIZE);
exit(student, course, CLASS_SIZE);
// ...
// NOTE: you should check to make sure the stream is in a good condition after each input - I leave the error checking code for you to implement
cout << "Student ID: ";
cin >> ar[i];
cout << "Student Grade: ";
cin >> arr[i]; // also note: since you are not using std::string, this can overflow! careful!
// ...
cout << "ID And Grade Of Student #" << i+1 << ":" << a[i] << "\t" << yo[i] << endl;