Week 1 practice: Bill Calculator

public class Bill {
    public static void main(String[] args) {
        double[] prices = {120.0, 45.5, 300.0};
        double total = 0;
        for (int i = 0; i < prices.length; i++) {
            total += prices[i];
        }
        double discount = 0;
        if (total >= 400) {
            discount = total * 0.10;
        }
        System.out.println("Total: " + total);
        System.out.println("Discount: " + discount);
        System.out.println("Pay: " + (total - discount));
    }
}

• A loop adds up all prices into total (465.5).
• An if gives a 10% discount when total is 400 or more.
• The final amount is printed using arithmetic.

Total: 465.5
Discount: 46.55
Pay: 418.95

• Challenge 1: Change the rule so bills of 1000 or more get 20% off, and 400–999 get 10%.
• Challenge 2: Use a loop to count how many items cost more than 100 and print the count.
• Challenge 3: Use a switch on a paymentMode number (1 = Cash, 2 = UPI, 3 = Card) to print the payment method.

Try it in your own Java setup or write it in the Practice Notebook.

1. 1. Which part of the program repeats for each price?

   iffor loopswitchmain

2. 2. What is 465.5 * 0.10?

   4.65546.55465.50.4655

3. 3. Which operator adds to total and stores it back?

   =++===++=