Java 如何在菜单循环后执行print语句，然后返回主菜单？

在printMenuItems方法中，当用户选择要添加到购物车中的项目时，程序应该循环。当用户处于“项目”菜单中时，程序应在底部显示“您当前的总计为：$”，直到用户选择返回主菜单。回到主菜单后，程序底部应显示“您的总到期日为：$”。目前，在程序返回主菜单之前，我有一个“Your total due is:$”语句正在执行，当用户返回时，该语句将“Your total due is”语句置于主菜单之上。我正在想办法把这句话放在主菜单下面

import java.util.Scanner;
public class Homework1 {

    static double userTotal = 0;
    static double userCredit = 100;
    static double [] menuPrices = {19.99, 29.49, 15.79, 24.99, 24.99};
    static Scanner myScanner = new Scanner(System.in);

    public static int printMainMenu() {
        System.out.println("Please select a menu item from the list below: \n" +
                "1 - View item menu \n" +
                "2 - Pay total due \n" +
                "3 - Add $5 in credit \n" +
                "4 - Clear order");

        int userChoice = myScanner.nextInt();
        if (userChoice > 0 && userChoice < 5) {
            return userChoice;
        }
        else {
            System.out.println("Please enter a valid option!");
            printMainMenu();
        }
        return 0;
    }

    public static double printMenuItems(double userTotal) {
        System.out.println("What would you like to add to your order? \n" +
                "(1) Toaster: $19.99 \n" +
                "(2) Coffee maker: $24.49 \n" +
                "(3) Waffle maker: $15.79 \n" +
                "(4) Blender: $24.99 \n" +
                "(5) Kettle: $24.99 \n" +
                "(6) Go to the main menu");
        System.out.println("Your current total is: $" + userTotal);
        int menuSelections = myScanner.nextInt();

        if (menuSelections == 1) {
            System.out.println("You have added a Toaster to your order.");
            userTotal += menuPrices[0];
        }
        else if (menuSelections == 2) {
            System.out.println("You have added a Coffee maker to your order.");
            userTotal += menuPrices[1];
        }
        else if (menuSelections == 3) {
            System.out.println("You have added a Waffle maker to your order.");
            userTotal += menuPrices[2];
        }
        else if (menuSelections == 4) {
            System.out.println("You have added a Blender to your order.");
            userTotal += menuPrices[3];
        }
        else if (menuSelections == 5) {
            System.out.println("You have added a Kettle to your order.");
            userTotal += menuPrices[4];
        }
        else if (menuSelections == 6) {
            System.out.println("Your total due is: $" + userTotal); 
            return userTotal;
        }
        else {
            System.out.println("Invalid item number please try again");
        }
        return printMenuItems(userTotal);

    }

    public static boolean payTotalDue(double userTotal) {
        double preTaxTotal = userTotal;
        if (preTaxTotal > 50) {
            preTaxTotal -= (preTaxTotal * 0.2);
            preTaxTotal += (preTaxTotal * 0.085);

            if (preTaxTotal <= userCredit) {
                System.out.println("Thank you! You saved: $" + (userTotal + (userTotal * 0.085) - preTaxTotal) +
                        " Your change is: $" + (userCredit - preTaxTotal));
                System.out.println("Your items will be on their way soon!");

            }
            else {
                System.out.println("Insufficient funds!");
                System.exit(0);
            }

        }
        else {
            preTaxTotal += (preTaxTotal * 0.085);
            System.out.println("Thank you! Your change is: $" + (userCredit - preTaxTotal));
            System.out.println("Your items will be on their way soon!");
        }
        return true;
    }

    public static void main(String[] args) {

        while (true) {
            int mainMenuSelection = printMainMenu();
            if (mainMenuSelection == 1) {
                userTotal = printMenuItems(userTotal);

            }
            else if (mainMenuSelection == 2) {
                if (payTotalDue(userTotal)) {
                    userTotal = 0;
                    break;
                }
            }
            else if (mainMenuSelection == 3) {
                userCredit += 5;
                System.out.println("Credit available: $" + userCredit);
            }
            else if (mainMenuSelection == 4) {
                System.out.println("Current order balance has been cleared. Current due: $0.00");
                userTotal = 0;
            }
        }
    }
}

import java.util.Scanner；
公共课家庭作业1{
静态双用户合计=0；
静态双用户信用=100；
静态双[]菜单={19.99,29.49,15.79,24.99,24.99}；
静态扫描仪myScanner=新扫描仪（System.in）；
公共静态int printmain菜单（）{
System.out.println（“请从下面的列表中选择一个菜单项：\n”+
“1-查看项目菜单\n”+
“2-应付款项总额\n”+
“3-在信用卡中添加$5\n”+
“4-明确命令”）；
int userChoice=myScanner.nextInt（）；
if（userChoice>0&&userChoice<5）{
返回用户选择；
}
否则{
System.out.println（“请输入有效选项！”）；
printmain菜单（）；
}
返回0；
}
公共静态双打印菜单项（double userTotal）{
System.out.println（“您希望向订单中添加什么？\n”+
“（1）烤面包机：$19.99\n”+
“（2）咖啡机：24.49美元\n”+
“（3）华夫饼制造商：$15.79\n”+
“（4）搅拌机：$24.99\n”+
（5）水壶：24.99美元\n+
“（6）进入主菜单”）；
System.out.println（“您当前的总数为：$”+userTotal）；
int menuSelections=myScanner.nextInt（）；
如果（菜单选择==1）{
System.out.println（“您在订单中添加了一个烤面包机。”）；
userTotal+=菜单[0]；
}
else if（menuSelections==2）{
System.out.println（“您在订单中添加了一个咖啡壶。”）；
userTotal+=菜单[1]；
}
else if（菜单选择==3）{
System.out.println（“您在订单中添加了一个华夫饼干制造商。”）；
userTotal+=menuPrices[2]；
}
else if（菜单选择==4）{
System.out.println（“您在订单中添加了一个搅拌机。”）；
userTotal+=菜单[3]；
}
else if（menuSelections==5）{
System.out.println（“您在订单中添加了一个水壶。”）；
userTotal+=菜单[4]；
}
else if（菜单选择==6）{
System.out.println（“您的到期总金额为：$”+userTotal）；
返回userTotal；
}
否则{
System.out.println（“无效项目编号，请重试”）；
}
返回printMenuItems（用户总数）；
}
公共静态布尔payTotalDue（double userTotal）{
double preTaxTotal=用户总数；
如果（税前合计>50）{
preTaxTotal-=（preTaxTotal*0.2）；
preTaxTotal+=（preTaxTotal*0.085）；
如果（preTaxTotal仅在集团下

 public static int printMainMenu() {
    System.out.println("Please select a menu item from the list below: \n" +
            "1 - View item menu \n" +
            "2 - Pay total due \n" +
            "3 - Add $5 in credit \n" +
            "4 - Clear order");

加

并从打印组中删除

 else if (menuSelections == 6) {
        System.out.println("Your total due is: $" + userTotal); 
        return userTotal;
    }

另外，使用java开关比使用其他许多开关更好/更简单

 switch (myScanner.nextInt()) {
            case 1:
                System.out.println("You have added a Toaster to your order.");
                userTotal += menuPrices[0];
                break;
            case 2:
                System.out.println("You have added a Coffee to your order.");
                userTotal += menuPrices[0];
                break;
            case 3: (continue with same..)
            default:
                System.out.println("Invalid item number please try again");
        }

根据问题，一旦您可以使用这个简单的代码片段，我如何运行代码打印输出

static boolean doOnce = true; //put this somewhere to be executed once , like begin of your program
...
if ( doOnce ) {
        System.out.println("Your total due is: $" + userTotal);
        doOnce = false;
}

因此，显然我需要“您的总到期日为：$”语句来显示，即使总到期日为$0.00。但是，当程序第一次启动并显示主菜单时，它不可能在那里。您知道我如何处理此问题吗？我更新了上面的答复，以包括runOnce代码块。也许这就是您正在寻找的。
static boolean doOnce = true; //put this somewhere to be executed once , like begin of your program
...
if ( doOnce ) {
        System.out.println("Your total due is: $" + userTotal);
        doOnce = false;
}