C++ Program To Make Bill Statement

Creating a bill statement program in C++ allows for efficient management and calculation of purchases. Such a program automates the process of tallying items, applying taxes, and determining the final amount due. In this article, you will learn how to develop a C++ program to generate a console-based bill statement.

Problem Statement

Businesses and individuals often need a clear, itemized record of goods or services purchased, including quantities, unit prices, and total cost. Manually calculating these can be time-consuming and prone to errors, especially when dealing with multiple items, taxes, and potential discounts. The core problem is to accurately and automatically generate a structured bill statement that summarizes all transaction details.

Example

Consider a simple bill statement for a few items:

--------------------------------------------------
                ABC Store - Bill
--------------------------------------------------
Item                  Qty     Price      Total
--------------------------------------------------
Laptop                  1   1200.00    1200.00
Mouse                   2     25.00      50.00
Keyboard                1     75.00      75.00
--------------------------------------------------
Subtotal:                        $1325.00
Tax (5%):                         $66.25
--------------------------------------------------
Total Amount Due:                $1391.25
--------------------------------------------------
Thank you for your purchase!

Background & Knowledge Prerequisites

To understand and implement the bill statement program, readers should have a basic understanding of:

• C++ Variables and Data Types: int, double, std::string.
• Input/Output Operations: Using std::cin for input and std::cout for output.
• Conditional Statements: if, else (optional, for error handling or choices).
• Looping Constructs: while or for loops for processing multiple items.
• Basic Arithmetic Operations: Addition, subtraction, multiplication.
• Standard Library Headers: Primarily , , and for formatting output.

Use Cases or Case Studies

A C++ bill statement program can be highly beneficial in various scenarios:

• Small Retail Shops: For generating quick receipts at the point of sale without needing complex POS systems.
• Freelancers and Consultants: To create invoices for services rendered, detailing work done and charges.
• Educational Projects: As a hands-on exercise for students learning C++ basics, reinforcing concepts like loops, data structures, and formatting.
• Inventory Management Support: Integrating with a basic inventory system to update stock levels as items are billed.
• Personal Budgeting: To track personal expenditures and categorize spending from custom receipts.

Solution Approaches

For creating a functional bill statement program, a straightforward console-based approach is most common for beginners due to its simplicity and directness in demonstrating core programming concepts.

Basic Console-Based Bill Statement

This approach involves taking item details (name, quantity, unit price) as input from the user, calculating the total for each item, summing up all totals to get a subtotal, applying a fixed tax rate, and finally displaying a formatted bill.

One-line summary: Develops a C++ console application that prompts for multiple item details, calculates individual item costs, a grand total with tax, and presents it in a structured bill format.

Code example:

// C++ Bill Statement Generator
#include <iostream>  // For input/output operations
#include <vector>    // To store multiple item details
#include <string>    // For item names
#include <iomanip>   // For output formatting (e.g., std::setprecision)

// Structure to hold item details
struct Item {
    std::string name;
    int quantity;
    double unitPrice;
    double total;
};

int main() {
    std::cout << "-------------------------------------------\\n";
    std::cout << "        Simple Bill Statement Generator    \\n";
    std::cout << "-------------------------------------------\\n";

    std::vector<Item> items; // A list to store all items
    char addMore = 'y';
    double grandSubtotal = 0.0;
    const double TAX_RATE = 0.05; // 5% tax rate

    // Step 1: Input item details from the user
    while (addMore == 'y' || addMore == 'Y') {
        Item newItem;
        std::cout << "\\nEnter Item Name: ";
        std::cin.ignore(); // Clear the buffer before reading string
        std::getline(std::cin, newItem.name);

        std::cout << "Enter Quantity: ";
        std::cin >> newItem.quantity;

        std::cout << "Enter Unit Price: $";
        std::cin >> newItem.unitPrice;

        newItem.total = newItem.quantity * newItem.unitPrice;
        grandSubtotal += newItem.total;
        items.push_back(newItem);

        std::cout << "Add another item? (y/n): ";
        std::cin >> addMore;
    }

    // Step 2: Display the formatted bill statement
    std::cout << "\\n\\n--------------------------------------------------\\n";
    std::cout << "                ABC Store - Bill                \\n";
    std::cout << "--------------------------------------------------\\n";
    std::cout << std::left << std::setw(20) << "Item"
              << std::right << std::setw(8) << "Qty"
              << std::right << std::setw(12) << "Price"
              << std::right << std::setw(12) << "Total\\n";
    std::cout << "--------------------------------------------------\\n";

    // Use fixed and setprecision for currency formatting
    std::cout << std::fixed << std::setprecision(2);

    for (const auto& item : items) {
        std::cout << std::left << std::setw(20) << item.name
                  << std::right << std::setw(8) << item.quantity
                  << std::right << std::setw(12) << item.unitPrice
                  << std::right << std::setw(12) << item.total << "\\n";
    }

    std::cout << "--------------------------------------------------\\n";
    double taxAmount = grandSubtotal * TAX_RATE;
    double finalTotal = grandSubtotal + taxAmount;

    std::cout << std::left << std::setw(40) << "Subtotal:"
              << std::right << "$" << std::setw(10) << grandSubtotal << "\\n";
    std::cout << std::left << std::setw(40) << "Tax (" + std::to_string(static_cast<int>(TAX_RATE * 100)) + "%):"
              << std::right << "$" << std::setw(10) << taxAmount << "\\n";
    std::cout << "--------------------------------------------------\\n";
    std::cout << std::left << std::setw(40) << "Total Amount Due:"
              << std::right << "$" << std::setw(10) << finalTotal << "\\n";
    std::cout << "--------------------------------------------------\\n";
    std::cout << "Thank you for your purchase!\\n";

    return 0;
}

Run

Sample output:

-------------------------------------------
        Simple Bill Statement Generator
-------------------------------------------

Enter Item Name: Laptop
Enter Quantity: 1
Enter Unit Price: $1200.00
Add another item? (y/n): y

Enter Item Name: Mouse
Enter Quantity: 2
Enter Unit Price: $25.00
Add another item? (y/n): y

Enter Item Name: Keyboard
Enter Quantity: 1
Enter Unit Price: $75.00
Add another item? (y/n): n


--------------------------------------------------
                ABC Store - Bill
--------------------------------------------------
Item                     Qty       Price      Total
--------------------------------------------------
Laptop                     1     1200.00    1200.00
Mouse                      2       25.00      50.00
Keyboard                   1       75.00      75.00
--------------------------------------------------
Subtotal:                                  $1325.00
Tax (5%):                                    $66.25
--------------------------------------------------
Total Amount Due:                          $1391.25
--------------------------------------------------
Thank you for your purchase!

Stepwise explanation for clarity:

1. Include Headers:
   • iostream for standard input/output.

1. Define Item Structure: A struct named Item is created to group related data for each product: name (string), quantity (int), unitPrice (double), and total (double).
2. Initialize Variables:
   • items: A std::vector to hold all the items the user enters.

1. Input Loop:
   • A while loop continuously prompts the user to enter item details until n (no) is entered.

1. Display Bill Header: Prints a formatted header for the bill, including column names for Item, Quantity, Price, and Total.
2. Format Output:
   • std::fixed and std::setprecision(2) are used to ensure all monetary values are displayed with exactly two decimal places.

1. Iterate and Display Items: A for loop iterates through the items vector, printing the details of each item in the defined format.
2. Calculate and Display Totals:
   • taxAmount is calculated by multiplying grandSubtotal by TAX_RATE.

Conclusion

Developing a C++ program for bill statements is an excellent way to practice fundamental programming concepts while creating a practical application. This solution demonstrates how to collect user input, perform calculations, manage data structures like vectors, and format output for clarity.

Summary

• A bill statement program automates the calculation and display of purchase details.
• Core C++ concepts like variables, loops, and structures are essential.
• The iostream, string, vector, and iomanip libraries are key for implementation.
• The program prompts for item details, calculates individual totals, sums them into a subtotal, applies tax, and presents a formatted bill.