Shopping Bill Calculator

Java Console Output

Planning Purchases

After buying something, do you ever regret having made the purchase? This is called buyer's remorse. Impluse spending can easily cause this. I was once told that if I ever suddenly really wanted to make an unplanned purchase, that I should wait two weeks. After two weeks, if I still felt like I needed the item, then it would probably be a wise purchase.

Writing the Code

Since many people tend to shop extravagantly, I decided it might be useful to learn how to program a shopping bill calculator. This program lets the user enter as many shopping items as they wish. When the user is done entering shopping items, it calculates the total cost plus 10% sales tax. To do this, it uses a while loop with an if statement at the end of it. Because it is an infinite loop, the while loop ends with an if statement. The if statement contains a break to get out of the loop. The only way to get out of the loop is when the user enters anything but “1” when asked if he/she desires to purchase another item.

Running the Code

Here's an example running the code:

Welcome to Shopping Bill Estimator!

Enter the name of the item you wish to purchase: Apples
Enter the cost of Apples in U.S. dollars: $1.99
Enter the number/amount of Apples you wish to buy: 10
Purchasing Apples will cost you $19.9.
Your estimated subtotal before taxes is: $19.9

Do you wish to add another product to your estimate? (Enter 1 for yes, or enter 2 for no): 1
Enter the name of the item you wish to purchase: Oranges
Enter the cost of Oranges in U.S. dollars: $.89
Enter the number/amount of Oranges you wish to buy: 15
Purchasing Oranges will cost you $13.35.
Your estimated subtotal before taxes is: $33.25

Do you wish to add another product to your estimate? (Enter 1 for yes, or enter 2 for no): 1
Enter the name of the item you wish to purchase: Milk
Enter the cost of Milk in U.S. dollars: $3.29
Enter the number/amount of Milk you wish to buy: 2
Purchasing Milk will cost you $6.58.
Your estimated subtotal before taxes is: $39.83

Do you wish to add another product to your estimate? (Enter 1 for yes, or enter 2 for no): 1
Enter the name of the item you wish to purchase: Cereal
Enter the cost of Cereal in U.S. dollars: $3.49
Enter the number/amount of Cereal you wish to buy: 4
Purchasing Cereal will cost you $13.96.
Your estimated subtotal before taxes is: $53.79

Do you wish to add another product to your estimate? (Enter 1 for yes, or enter 2 for no): 1
Enter the name of the item you wish to purchase: Eggs
Enter the cost of Eggs in U.S. dollars: $1.39
Enter the number/amount of Eggs you wish to buy: 3
Purchasing Eggs will cost you $4.17.
Your estimated subtotal before taxes is: $57.96

Do you wish to add another product to your estimate? (Enter 1 for yes, or enter 2 for no): 2
Your total estimate, including taxes is $63.756

Code for the Bill Calculator

package grocerybillcost;

import java.util.Scanner;

/**
 *
 * @author Bahr
 */
public class GroceryBillCost {

    public static void main(String[] args){
		
        Scanner input = new Scanner(System.in); // Puts the scanner to work.
        System.out.println("Welcome to Shopping Bill Estimator!");
	int addItem = 1; // Declares an integer variable "addItem"
        double subTotal = 0; // Declares a double varialbe "subTotal";
	
        // This loop calculates the cost of purchasing the items entered by the user and adds it to previously entered items. 
	while (true) {
            System.out.print("Enter the name of the item you wish to purchase: ");
            String itemName = input.next(); // User enters the name of the item.
            System.out.print("Enter the cost of " + itemName + " in U.S. dollars: $");
            double itemPrice = input.nextDouble(); // User enters the price of the item.
            System.out.print("Enter the number/amount of " + itemName + " you wish to buy: ");
            double itemAmount = input.nextDouble(); // User enteres the amount to buy.
            double itemCost = (itemPrice * itemAmount); // Calculates the total price for buying multiples of the same item.
            System.out.println("Purchasing " + itemName + " will cost you $" + itemCost + ".");
            subTotal = (itemCost + subTotal); // Adds the cost of the current item to previously entered items. 
            System.out.println("Your estimated subtotal before taxes is: $" + subTotal);
            System.out.print("Do you wish to add another product to your estimate? (Enter 1 for yes, or enter 2 for no): ");
            addItem = input.nextInt(); // Takes the number the user enters.
            
            // Loop continues if the user enters 1. If 1 is entered, it will ask for the next item.
            if(addItem == 1) {
                continue;
            }
            else {
                break;
            }
        }

        
	double totalBill = ((subTotal * 0.1) + subTotal); // Calculates the entire bill including tax.    
	System.out.println("Your total estimate, including taxes is $" + totalBill);
    
    }
}

For more information on Java, see Oracle's Java Tutorials