好吧，所以我已经有点陷入这个问题，你需要得到小计并添加它们，但每当我输入它们时，我最终得到最后输入的值。
示例输入：
1，早餐
然后
1-59.00
2，无
（返回bfast菜单）
3-35.00
（应该是59 + 35）
然后退出，然后当我输入现金并获得更改时，我总是得到35.00输入。
package finalsProject;
import java.text.DecimalFormat;
import javax.swing.*;
/* Program Name: Menu Bar
* Program Version: 1.2b
* Programmed By: Lance Cyril L. Luchico
* Modified By: Ivan Aldwin A. Cristobal
*
* This Program enables the user to select from a wide variety
* of food choices using the provided menus in the program.
* The program is created using OOP, and is divided into 4 methods.
* First-Breakfast, Second-Lunch, Third Dinner, and fourth, The Checkout.
*
* This Program has its parts interchanged from two menu programs
* for a better functionality.
*
*/
public class Menu {
static float sub , vat = 0.12f , total , pay , change ;
static int meal , choice , order , add, addorders, comporders ;
static DecimalFormat df=new DecimalFormat("#.00");
public static void showMenu(){
{
meal = Integer.parseInt(JOptionPane.showInputDialog(null,"Mcdonalds"
+ "\nChoose your Meal"
+ "\n[1] Breakfast"
+ "\n[2] Lunch"
+ "\n[3] Dinner"));
if (meal == 1)
Breakfast(meal);
else if (meal == 2)
Lunch(meal);
else if (meal == 3)
Dinner(meal);
}
}
public static void Breakfast(int meal){
choice = Integer.parseInt(JOptionPane.showInputDialog(null,"Breakfast Choices"
+ "\n[1] Hamburger Mcdo \t59.00"
+ "\n[2] Breakfast Deluxe \t99.00"
+ "\n[3] Chicken Muffin \t35.00"
+ "\n[4] Egg McMuffin \t49.00"
+ "\n[5] Apple Pie \t39.00"));
order = Integer.parseInt(JOptionPane.showInputDialog(null,"How many orders?"));
if (choice == 1){
sub = 59 * order;
}
else if (choice == 2){
sub = 99 * order;
}
else if (choice == 3){
sub = 35 * order;
}
else if (choice == 4){
sub = 49 * order;
}
else if (choice == 5){
sub = 39 * order;
}
addorders = Integer.parseInt(JOptionPane.showInputDialog("Any Additional Orders?:"
+ "\n[1]Yes"
+ "\n[2]No"
+ "\nChoice: "));
if(addorders == 1){
showMenu();
}
else if(addorders == 2){
comporders = Integer.parseInt(JOptionPane.showInputDialog("Orders Complete? "
+ "\n[1]Yes"
+ "\n[2]No"));
if(comporders == 1)
Checkout();
if(comporders == 2)
Breakfast(meal);
}
}
public static void Lunch(int meal){
choice = Integer.parseInt(JOptionPane.showInputDialog(null,"Lunch Choices"
+ "\n[1] Chicken McNuggets \t59.00"
+ "\n[2] Double McSpicy \t59.00"
+ "\n[3] French Fries \t99.00"
+ "\n[4] McWings \t79.00"
+ "\n[5] Coke \t29.00"));
order = Integer.parseInt(JOptionPane.showInputDialog(null,"How many orders?"));
if (choice == 1){
sub = 59 * order;
}
else if (choice == 2){
sub = 59 * order;
}
else if (choice == 3){
sub = 99 * order;
}
else if (choice == 4){
sub = 79 * order;
}
else if (choice == 5){
sub = 35 * order;
}
addorders = Integer.parseInt(JOptionPane.showInputDialog("Any Additional Orders?:"
+ "\n[1]Yes"
+ "\n[2]No"
+ "\nChoice: "));
if(addorders == 1){
showMenu();
}
else if(addorders == 2){
comporders = Integer.parseInt(JOptionPane.showInputDialog("Orders Complete? "
+ "\n[1]Yes"
+ "\n[2]No"));
if(comporders == 1)
Checkout();
if(comporders == 2)
Lunch(meal);
}
}
public static void Dinner(int meal){
choice = Integer.parseInt(JOptionPane.showInputDialog("Dinner Choices"
+ "\n[1] Mocha Frappe \t59.00"
+ "\n[2] Garden Side Salad \t29.00"
+ "\n[3] McDouble \t89.00"
+ "\n[4] McSpicy \t99.00"
+ "\n[5] CheeseBurger \t35.00"));
order = Integer.parseInt(JOptionPane.showInputDialog("How many orders?"));
if (choice == 1){
sub = 59 * order;
}
else if (choice == 2){
sub = 29 * order;
}
else if (choice == 3){
sub = 89 * order;
}
else if (choice == 4){
sub = 99 * order;
}
else if (choice == 5){
sub = 35 * order;
}
addorders = Integer.parseInt(JOptionPane.showInputDialog("Any Additional Orders?:"
+ "\n[1]Yes"
+ "\n[2]No"
+ "\nChoice: "));
if(addorders == 1){
showMenu();
}
else if(addorders == 2){
comporders = Integer.parseInt(JOptionPane.showInputDialog("Orders Complete? "
+ "\n[1]Yes"
+ "\n[2]No"));
if(comporders == 1)
Checkout();
if(comporders == 2)
Dinner(meal);
}
}
public static void Checkout(){
pay = Integer.parseInt(JOptionPane.showInputDialog("Enter your Money"));
vat = sub * vat;
total = sub + total;
change = pay - total;
if (pay > total){
JOptionPane.showMessageDialog(null,"Subtotal : " + df.format(sub)
+ "\nVAT : " + df.format(vat)
+ "\nTotal : " + df.format(total)
+ "\nCash : " + df.format(pay)
+ "\nChange : " + df.format(change));
}
else if (pay < total){
JOptionPane.showMessageDialog(null,"Unable to Continue Transaction, Insufficient Funds");
}
}
}
答案 0 :(得分：0)
您正在为sub分配值，而不是添加它们而非执行
sub = ...
使用
sub += ...
这会将价格加到小计
在旁注上使所有方法保持静态基本上违背了OOP的目的。