我是一个初学者,所以我得到的结果是我的 if else 语句的一个条件让我大吃一惊。除了 QtyCalc 变量 >= 100 的情况外,一切正常。 Finprice 变量被列为磁盘变量,我不知道为什么。帮助?
import javax.swing.JOptionPane;
public class SoftwareSales {
public static void main(String[] args) {
final int price = 99;
String Qty;
double QtyCalc, preprice, Finprice, disc;
Qty = JOptionPane.showInputDialog(null, "How many packages will you buy?");
QtyCalc = Double.parseDouble(Qty);
preprice = QtyCalc * price;
if (QtyCalc >= 100) {
disc = (preprice * (0.5));
Finprice = (preprice - disc);
JOptionPane.showMessageDialog(null, "Your discount is: " + disc + ".\n" + "Your final price is: " + Finprice + ". ");
} else if (QtyCalc >= 50 && QtyCalc <= 99) {
disc = (preprice * 0.4);
Finprice = (preprice - disc);
JOptionPane.showMessageDialog(null, "Your discount is: " + disc + ".\n" + "Your final price is: " + Finprice + ". ");
} else if (QtyCalc >= 20 && QtyCalc <= 49) {
disc = (preprice * 0.3);
Finprice = (preprice - disc);
JOptionPane.showMessageDialog(null, "Your discount is: " + disc + ".\n" + "Your final price is: " + Finprice + ". ");
} else if (QtyCalc >= 10 && QtyCalc <= 19) {
disc = (preprice * 0.2);
Finprice = (preprice - disc);
JOptionPane.showMessageDialog(null, "Your discount is: " + disc + ".\n" + "Your final price is: " + Finprice + ". ");
} else if (QtyCalc < 10 && QtyCalc >= 1) {
disc = 0;
Finprice = 0;
JOptionPane.showMessageDialog(null, "Sorry, there is no discount for purchases less than 10." + " Your price is: " + preprice);
} else {
JOptionPane.showMessageDialog(null, "You have entered an invalid number.");
}
disc = 0;
Finprice = 0;
System.exit(0);
}
}