Question

The program I code below should
List all payment made by each student, show amount paid and outstanding

I need some help with the following section:

void payment()
{
    // Display message asking for the user input
    std::cout << "List all payment made by each student, show amount paid and outstanding." << std::endl;

    // Read from text file and Display list of payment

    std::ifstream infile;               // enable to open, read in and close a text file
    float StudentCode;                  // to store the student enrolment number
    float Amount;                       // to store the amount of money
    float Type;                         // to store information on type of payment made
    float Outstanding;                  // to store amount of money is due

    infile.open("Payment.txt");         // open a text file called Payment

    if (!infile)                 
    {
        std::cout << "Item list is empty" << std::endl;     // if the file is empty it output the message
    } 
    else 
    {
        std::cout << "List of Payment: " << std::endl;
        std::cout << "" << std::endl;
        std::cout << "Enrolment No." << "Amount" << "Outstanding" << std::endl;

        // If there is Student Code that has the same number, it need to combined the amount it paid 
        // For an example 
        // Student Code: 12 Amount: 25
        // Student Code: 12 Amount: 50
        // so it should display the following when the program runs:
        // Student Code: 12 Amount: 75

        while(!infile.eof())            // output the description of the text file onto the screen
        {
            getline(infile,StudentCode,Amount);

            Outstanding = Amount - 100;

            std::cout << StudentCode << Amount << "$" << Outstanding << std::endl;
            //iter++;
        }
        std::cout << "End of list\n" << std::endl;
    }

    infile.close();         // close the text file  
}

What is wrong with the getline part:

getline(infile,StudentCode, Amount);

Also the program should not display repeated Student Code but combine the amount it paid.
Where I explain in the comment section

// If there is Student Code that has the same number .....

How do I do this?

Answer 1

getline reads a line from a stream into a string. What you’re trying to do, is more like this

while (infile >> StudentCode >> Amount) {
    // process values
}

If you want to sum up all amounts, you must first accumulate and afterwards loop through the collected values and print them

std::map<int, float> amountsPaid;
int studentCode;
float amount;
// accumulate amounts
while (infile >> studentCode >> amount) {
    amountsPaid[studentCode] += amount;
}

// loop through map and print all entries
for (auto i = amountsPaid.begin(); i != amountsPaid.end(); ++i) {
    float outstanding = i->second - 100;
    std::cout << i->first << ": " << i->second << "$, " << outstanding << '\n';
}