Example: Basic Fixed-Item Bill in C

// Basic Fixed-Item Bill
#include <stdio.h>

int main() {
    // Step 1: Declare variables for item details and calculations
    char customerName[50];
    int qtyLaptop, qtyMouse, qtyKeyboard;
    float priceLaptop = 1200.00;
    float priceMouse = 25.00;
    float priceKeyboard = 75.00;
    float totalLaptop, totalMouse, totalKeyboard, subtotal;

    // Step 2: Get customer name
    printf("Enter Customer Name: ");
    // Use fgets to safely read a line of text including spaces
    // stdin is the standard input stream
    // 49 is the max characters to read (50 - 1 for null terminator)
    fgets(customerName, sizeof(customerName), stdin);
    // Remove the trailing newline character if present
    for (int i = 0; customerName[i] != '\0'; i++) {
        if (customerName[i] == '\n') {
            customerName[i] = '\0';
            break;
        }
    }

    // Step 3: Get quantities for each item
    printf("Enter Quantity for Laptop (%.2f each): ", priceLaptop);
    scanf("%d", &qtyLaptop);
    printf("Enter Quantity for Mouse (%.2f each): ", priceMouse);
    scanf("%d", &qtyMouse);
    printf("Enter Quantity for Keyboard (%.2f each): ", priceKeyboard);
    scanf("%d", &qtyKeyboard);

    // Step 4: Calculate total for each item
    totalLaptop = qtyLaptop * priceLaptop;
    totalMouse = qtyMouse * priceMouse;
    totalKeyboard = qtyKeyboard * priceKeyboard;

    // Step 5: Calculate subtotal
    subtotal = totalLaptop + totalMouse + totalKeyboard;

    // Step 6: Print the bill statement
    printf("\n--- Bill Statement ---\n");
    printf("Customer Name: %s\n", customerName);
    printf("----------------------------------------\n");
    printf("%-15s %-5s %-10s %-10s\n", "Item", "Qty", "Price", "Total");
    printf("----------------------------------------\n");
    printf("%-15s %-5d %-10.2f %-10.2f\n", "Laptop", qtyLaptop, priceLaptop, totalLaptop);
    printf("%-15s %-5d %-10.2f %-10.2f\n", "Mouse", qtyMouse, priceMouse, totalMouse);
    printf("%-15s %-5d %-10.2f %-10.2f\n", "Keyboard", qtyKeyboard, priceKeyboard, totalKeyboard);
    printf("----------------------------------------\n");
    printf("%-32s %-10.2f\n", "Subtotal:", subtotal);
    printf("----------------------------------------\n");

    return 0;
}