Reference Variables I really dont understand

[Skyreminisce]

Hello everyone,

Im having a difficulty of what is the use of reference variables and how to use it specially in gaming can someone give me a brief explanation to it...I study advanced in c++ before going to college and Im new to C++ im not even a month so please help me..

#include <iostream>

using namespace std;

void getScore(int& score);
void printGrade(int score);

int main()
{
    int courseScore;

    getScore(courseScore);
    printGrade(courseScore);

    return 0;
}

void getScore(int& score)
{
   cout << "Enter score: ";
   cin >> score;
   cout << "Score is: " << score << endl;
}

void printGrade(int cScore)
{
   cout << "Your grade is: ";

   if(cScore >= 90)
     cout << "A." << endl;
   else if(cScore >=80)
     cout << "B." << endl;
   else if(cScore >= 70)
     cout << "C." << endl;
   else if(cScore >= 60)
     cout << "D." << endl;
   else
     cout << "F." << endl;
}

This as for instance, what if there will be no reference parameter and also is there any alternative way to do same output without using the reference parameter?

[Zhuge]

If you want to avoid references, you could replicate the behavior with a pointer. However, there is no guaranteeing that pointer is non-NULL or even valid. The point of a reference parameter is that you will actually be modifying the parameter you pass in, instead of simply getting a copy of its value to work with.

[Peter87]

A reference is used here so that changes to score inside getScore will also change courseScore in main.
You can write the program without references by using a return value instead.

...

int main()
{
    int courseScore;

    courseScore = getScore();
    printGrade(courseScore);

    return 0;
}

int getScore()
{
   cout << "Enter score: ";
   cin >> score;
   cout << "Score is: " << score << endl;
   return score;
}

...