(Yes this WAS homework, but already completed, I'm just trying to improve it now for practice)
This is basically a sales calculator, that allows you to have multiple inputs for sales items, then displays the total, sales tax, and grand total.
The modification I'm trying to make, is that I want to be able to SAVE the cost of each number of items in a variable, without them overlapping memory, and then be able to call them above the grand total, so you can see what each item was worth.
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//importing libraries for cin and cout, as well as setw() and setprecision()
#include <iostream>
#include <iomanip>
using namespace std; //sets all code to standard syntax
int main(){ //initializes the main function
//initializing variables
char answer = ' ';
int saleItems = 0;
double saleTax = 0.0;
double grandTotal = 0.0;
double itemValue = 0.0;
double titemValue = 0.0;
double taxPerc = 0.0;
//begins a post-test loop
do {
titemValue = 0.0; //makes sure the accumulator resets WITHIN the loop
//prompts for sale items amount
cout << "How many sales items do you have? : ";
cin >> saleItems;
//creates a loop that displays the prompt for each iteration of saleItems
for (int x = 1; x <= saleItems; x += 1){
cout << "Enter in the value of sales item " << x << " : $";
cin >> itemValue;
titemValue += itemValue; //accumulator for adding up the iterated values
}
//prompts the user to enter a sales percentage
cout << endl << endl;
cout << "Enter in the sales tax percentage(Enter 10 for 10%): ";
cin >> taxPerc;
cout << endl << endl;
//processes the variables after taxPerc has been given
saleTax = titemValue * (taxPerc / 100);
grandTotal = titemValue + saleTax;
//sets decimal precision to 2 places
cout << fixed << setprecision(2);
//displays receipt with the calculated and input values
cout << "********************************************" << endl;
cout << "******** S A L E S R E C E I P T ********" << endl;
cout << "********************************************" << endl;
cout << "** **" << endl;
cout << "** **" << endl;
cout << "** **" << endl;
cout << "** **" << endl;
cout << "** Total Sales $" << setw(9) << titemValue << " **" << endl;
cout << "** Sales Tax $" << setw(9) << saleTax << " **" << endl;
cout << "** ---------- **" << endl;
cout << "** Grand Total $" << setw(9) << grandTotal << " **" << endl;
cout << "** **" << endl;
cout << "** **" << endl;
cout << "********************************************" << endl << endl << endl;
//prompts user to begin loop again
cout << "Do you want to run this program again? (Y/N):";
cin >> answer;
answer = toupper(answer);
cout << endl << endl;
} while (answer == 'Y');
===========================================================================
So, essentially, I need to be able to save each itemValue to multiple different values without the loop repeating itself, and just replacing them, and I can't really see how I can do that considering the accumulator will just keep looping, and adding up the itemValue values.
Here is one way to use an simple array to store the item values.
Declare an array at the top. Note: you will have to give it a fixed size. There are ways to have a variable size, but they get more complex (such as vectors). It is better to specify the size using a constant, rather than a hard coded number, as you will need the constant later.
const int maxSaleItems = 100;
double itemValues[maxSaleItems];
After you have asked the user for the number of items, max sure they haven't entered a number that is too big.
cout << "How many sales items do you have? : ";
cin >> saleItems;
if (saleItems > maxSaleItems) {
cout << "Sorry, I can only handle " << maxSaleItems << " items.";
continue;
}
Inside the loop where you are inputting the item values, save the item value to the array:
cout << "Enter in the value of sales item " << x << " : $";
cin >> itemValue;
titemValue += itemValue; //accumulator for adding up the iterated values
itemValues[x - 1] = itemValue;
Note the x-1 in the array access - arrays are 0 based (i.e. their index starts from 0). Normally I would loop x from 0 to < saleItems, but I didn't want to change your existing loop.
When printing the receipt, add a loop which prints out all the values (you will need to add formatting):
cout << "** **" << endl;
for (int x = 1; x <= saleItems; x += 1){
cout << "** Item " << x << " $" << itemValues[x-1] << " **" <<endl;
}
cout << "** **" << endl;
As I said in the comments, using std::vector would be better, but if you aren't up to that yet, arrays will do.
Edit: Simple vector example.
To add vectors you need to include the appropriate header:
#include <vector>
No need for maxSaleItems any more, as vectors can grow. Declare the vector variable. The <double> makes it a vector that contains double values:
std::vector<double> itemValues;
Inside the loop, instead of setting the array value for the new item by location, just add it to the end of the vector using push_back.
cout << "Enter in the value of sales item " << x << " : $";
cin >> itemValue;
titemValue += itemValue; //accumulator for adding up the iterated values
itemValues.push_back(itemValue);
The printing receipt code, can be left exactly as it was for the array version, as you can access vectors like arrays:
cout << "** **" << endl;
for (int x = 1; x <= saleItems; x += 1){
cout << "** Item " << x << " $" << itemValues[x-1] << " **" <<endl;
}
cout << "** **" << endl;
There are other changes you could do to make the vector version simpler, but I wanted to change as little as possible.