Real World Example

Example

public class Main {
    public static void main(String[] args) {
        double shirtPrice = 799;
        int shirtQty = 2;
        double jeansPrice = 1499;
        int jeansQty = 1;
        boolean isFirstOrder = true;

        double subtotal = shirtPrice * shirtQty + jeansPrice * jeansQty;
        double discount = (isFirstOrder && subtotal >= 2000) ? subtotal * 0.10 : 0;
        double afterDiscount = subtotal - discount;
        double delivery = afterDiscount >= 499 ? 0 : 40;
        double gst = afterDiscount * 0.05;
        double total = afterDiscount + delivery + gst;

        System.out.println("Subtotal : " + subtotal);
        System.out.println("Discount : -" + discount);
        System.out.println("Delivery : " + delivery);
        System.out.printf("GST (5%%) : %.2f%n", gst);
        System.out.printf("To pay   : %.2f%n", total);
    }
}

Output

Subtotal : 3097.0
Discount : -309.70000000000005
Delivery : 0.0
GST (5%) : 139.37
To pay   : 2926.67