C++ Structures regarding corporate sales

Question

This program uses a structure to store the following data on a company division:

Division Name(such as East, West, North, or South)

Quarter(1, 2, 3, or 4)

Quarterly Sales

The user should be asked for the four quarters' sales figures for the East, West, North, and South divisions, and the data should be stored in the structure. This is my code so far, I'm not understand the concept properly:

#include "stdafx.h"
#include <iostream>
#include <fstream>

using namespace std;

struct Data{

    char *name;
    int quarter[4];
    int sales;

};

int _tmain(int argc, _TCHAR* argv[])
{
    Data division[4];
    int count;

    division[0].name = "East";
    division[1].name = "West";
    division[2].name = "North";
    division[3].name = "South";

    for(count = 0; count < 4; count++){

        cout << "Please enter the sales for the " << division[count].name << " for: " << endl;
        cout << "Quarter: " << count + 1 << ": " << endl;
        cin >> division[count].quarter[count].sales;


    }

    cin.get();
    return 0;
}

It seems my for loop is not working at all, something is wrong with my cin statement, because `division is showing a red underline.

Answer 1

Replace

cin >> division[count].quarter[count].sales;

with

cin >> division[count].sales;

But your application structure is... fishy at least. What's the point of the quarter array?

Answer 2

In your original you are going to overflow your quarter array... This is dangerous and undefined behaviour and can lead to memory corruption that will pop up at a later time and mess your program up. How are you going to overflow? Well, when your count value goes to "3" you are going to address your quarter array with quarter[3+1] = quarter[4]. This is ONE more than the array holds (from 0 -> 3) and this memory address will get written to. What is in that address? We don't know.

It looks like you should have a nested for loop for the quarters:

for(int div_i = 0; div_i < 4; ++div_i)
{
    for(int qt_i; st_i < 4; ++qt_i)
    {
        cout << "Please enter the sales for the " << division[div_i].name << " for: " << endl;
        cout << "Quarter: " << qt_i << ": " << endl;
        cin >> division[div_i].quarter[qt_i].sales;
    }
}

That would leave you with the individual quarter sales for each division.

Also you should use a const uint8 for your array sizes:

const unsigned char _DIVISION_COUNT = 4;
const unsigned char _QUARTER_COUNT = 4;

// and your loops become:
for( int count = 0; count < _DIVISION_COUNT; ++count)...

Makes it clear to someone who would use/maintain your code after you what you are doing.

Answer 3

You've got a couple of problems with the structure you defined.

First, what is the type of the sales data. You're specifying integers, but is the sales really a decimal number (many cash examples use doubles for money representations)?

Second, I am a little suspicious of the problem statement. Your structure example involves an array, but the problem statement halfway suggests that each structure will have a single indicator of what quarter it represents. This would make the structures more like database records.

Here are two possible approaches:

typedef double money_t;

struct sales_datum {
    std::string division; // North, East, South, West
    int quarter; // 1, 2, 3, 4
    money_t sales;
};

The above approach seems to comply with the problem statement a little more. Each of these structures would hold one piece of sales data - for a particular division for a particular quarter.

Alternatively,

struct sales_datum {
    std::string division; // North, East, South, West
    money_t sales_for_quarter[4]; 
};

This seems to be more like what you were trying in your original post. The struct now holds sales data for one division for an entire year (four quarters).

Using the second type will tend to make your code go in certain directions - it's easier to think about filling in the entire structure before moving on to another one, so you'll want to collect all the data for a year for one division before moving on to the next.

Answer 4

A structure is a very simple definition of a class. Think of it as a class without any methods, just instance variables.

What you're doing there is asking, for each division, what the sales are for each quarter.

So in every division you have 4 different sales, pertaining to each quarter. Those are saved in your structure.

Answer 5

You are using the same variable to loop over both divisions & quarters (both times count).