Calculate total gross pay of 10 employees. (C++ - Array in Struct)

Question

The result of this question, it should have a payroll record consists all of these things. But i have a problem in calculating the TOTAL GROSS PAY FOR ALL EMPLOYEES by using arrays in struct (C++) but I am stuck. The total gross pay should be printed at bottom of the payroll record. I feel like something is missing in my coding but I can`t figure out what that thing is. I only have a problem in finding the total gross pay, others are okay.

#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
    double gross[10];
    double sum = 0.0;
    double totalGrossPay;
    struct GrossPay {
        int empID;
        string empName;
        double chargeHour;
        int workingHours;
        double grossPay;
    };

    GrossPay employee[10];

    for (int i = 0; i < 10; i++) {
        cout << (i + 1) << "."
             << "Employee Name :";
        cin >> employee[i].empName;

        cout << "Employee ID :";
        cin >> employee[i].empID;

        cout << "Employee`s charge rate per hour :";
        cin >> employee[i].chargeHour;

        cout << "Working hours :";
        cin >> employee[i].workingHours;

        cout << endl;
    }
    cout << "Employee ID\t"
         << "Employee Name\t"
         << "Gross Pay(RM)" << endl;
    for (int i = 0; i < 10; i++) {
        double gross = employee[i].chargeHour * employee[i].workingHours;
        cout << employee[i].empID << "\t\t" << employee[i].empName << "\t\t" << gross;
        cout << endl;
    }
    cout << endl;

    for (int i = 0; i < 10; i++) {
        totalGrossPay = sum + gross[i];
    }
    cout << "Total gross pay of 10 employees : RM" << totalGrossPay;
    return 0;
}

`cin >> employee[i].empName;` could be a bug. Do the names include only a first name? Remember that `cin >> employee[i].empName;` reads up to the first whitespace character. — drescherjm, Nov 02 '21 at 14:11
`double gross = employee[i].chargeHour * employee[i].workingHours;` maybe you wanted to make use of the array of the same name you declared above but did not use. — drescherjm, Nov 02 '21 at 14:14
Yeaa, I just noticed that. Thank you so much for helping me. It works! — Anis Amira, Nov 02 '21 at 15:45
I added 0 to initialise the variable. So I guess not every variable needs to initialise the value, right? — Anis Amira, Nov 02 '21 at 15:50
If you are going to use it you better initialize it otherwise you have undefined behavior. But why add 0 to a number? `sum` is always 0. — drescherjm, Nov 02 '21 at 15:53
Oh, I see what you meant to do. The answer explains what you need to change to fix the total. — drescherjm, Nov 02 '21 at 15:54
Another question from me. "cin >> employee[i].empName; reads up to the first whitespace character" - can you explain this to me? Because my lecturer never mention it to his students about it before. So I tried to run the program by putting first and last name and surprisingly, the information turned out incorrect. — Anis Amira, Nov 02 '21 at 16:02
Related: [https://stackoverflow.com/questions/5838711/stdcin-input-with-spaces](https://stackoverflow.com/questions/5838711/stdcin-input-with-spaces) and after you switch to use std::getline to read a name please read this: [https://stackoverflow.com/questions/21567291/why-does-stdgetline-skip-input-after-a-formatted-extraction](https://stackoverflow.com/questions/21567291/why-does-stdgetline-skip-input-after-a-formatted-extraction) — drescherjm, Nov 02 '21 at 16:08
See the answer from chris in this question for a better explanation: [https://stackoverflow.com/questions/11462021/issue-with-cin-when-spaces-are-inputted-using-string-class](https://stackoverflow.com/questions/11462021/issue-with-cin-when-spaces-are-inputted-using-string-class) — drescherjm, Nov 02 '21 at 16:11

Vlad from Moscow · Accepted Answer · 2021-11-02T14:18:12.157

You have an uninitialized array

double gross[10];

So its elements have indeterminate values.

As a result this loop

for (int i = 0; i < 10; i++) {
    totalGrossPay = sum + gross[i];
}

invokes undefined behavior.

Also the variable sum has not changed in the preceding code. So its using in this for loop does not make a sense.

Maybe you mean in the body of the loop

double totalGrossPay = 0.0;

for (int i = 0; i < 10; i++) {
    totalGrossPay += gross[i];
}

provided that the array gross is filled with values.

It seems that in this for loop

for (int i = 0; i < 10; i++) {
    double gross = employee[i].chargeHour * employee[i].workingHours;
    cout << employee[i].empID << "\t\t" << employee[i].empName << "\t\t" << gross;
    cout << endl;
}

you mean elements of the array gross instead of the local variable gross as for example

for (int i = 0; i < 10; i++) {
    gross[i] = employee[i].chargeHour * employee[i].workingHours;
    cout << employee[i].empID << "\t\t" << employee[i].empName << "\t\t" << gross[i];
    cout << endl;
}

Also the data member double grossPay; of the structure is not used. Maybe instead of the array gross you need to fill this data member of elements of the array of structures do not you?

Yupp, I just noticed that. Thank you so much for your help! Finally, it works! — Anis Amira, Nov 02 '21 at 15:45

Calculate total gross pay of 10 employees. (C++ - Array in Struct)

1 Answers1