Java 我如何在这里实现多次尝试

我问用户是否有促销代码，如果有，我给他机会输入，我想让他有3次正确的输入尝试

我就是这样尝试的：

public void chooseClassAndPromoCode(ArrayList<Flight> flightList) {
    System.out.println("Pick which class do you want? (1 - economic, 2 - business, 3 - first class)");
    int userFlightClass = scanner.nextInt();
    scanner.nextLine();

    System.out.println("Do you have promo code? (yes / no )");
    String yesNoPromoCode = scanner.nextLine();
    int attempts = 3;
    if (yesNoPromoCode.equalsIgnoreCase("yes")) {
        System.out.println("Enter promo code");
        String userPromoCode = scanner.nextLine();

        while (attempts-- > 0) {
            if (userPromoCode.equals(selectedFlight.getPromoCode()) && userFlightClass == 1) {
                System.out.println("Price for economic class is: " + selectedFlight.getPriceForEconomicClass());
               // System.out.println("Promo code is valid. You have discount of: 20%, new price is: " + discountEconomyClass());
                System.out.println("Balance of: " + selectedPassenger.getFirstName() + " is: " + selectedPassenger.getBalance());
          //      payingEconomicClassWithPromoCode(flightList);
            } else {
                System.out.println("Incorrent. Number of atempts: " + attempts);
            }
        }
    }
}

---

只需修复

userPromoCode

扫描仪的位置，它应该在

while

中

public void chooseClassAndPromoCode(ArrayList<Flight> flightList) {
System.out.println("Pick which class do you want? (1 - economic, 2 - business, 3 - first class)");
int userFlightClass = scanner.nextInt();
scanner.nextLine();

System.out.println("Do you have promo code? (yes / no )");
String yesNoPromoCode = scanner.nextLine();
int attempts = 3;
String userPromoCode = ""
if (yesNoPromoCode.equalsIgnoreCase("yes")) {
    while (attempts-- > 0) {
        System.out.println("Enter promo code");
        userPromoCode = scanner.nextLine();
        if (userPromoCode.equals(selectedFlight.getPromoCode()) && userFlightClass == 1) {
            System.out.println("Price for economic class is: " + selectedFlight.getPriceForEconomicClass());
           // System.out.println("Promo code is valid. You have discount of: 20%, new price is: " + discountEconomyClass());
            System.out.println("Balance of: " + selectedPassenger.getFirstName() + " is: " + selectedPassenger.getBalance());
      //      payingEconomicClassWithPromoCode(flightList);
              break;
        } else {
            System.out.println("Incorrent. Number of atempts: " + attempts);
        }
    }
}

public void选择ClasssandPromoCode（ArrayList飞行列表）{
println（“选择您想要哪一类？（1-经济舱，2-商务舱，3-头等舱）”；
int userFlightClass=scanner.nextInt（）；
scanner.nextLine（）；
System.out.println（“您有促销代码吗？（是/否）”）；
字符串yesNoPromoCode=scanner.nextLine（）；
int=3；
字符串userPromoCode=“”
如果（是PromoCode.equalsIgnoreCase（“是”））{
同时（尝试-->0）{
System.out.println（“输入促销代码”）；
userPromoCode=scanner.nextLine（）；
if（userPromoCode.equals（selectedFlight.getPromoCode（））&&userFlightClass==1）{
System.out.println（“经济舱的价格为：+selectedFlight.getPriceForEconomicClass（））；
//System.out.println（“促销代码有效，折扣为：20%，新价格为：“+DiscountEnteconomyClass（）”）；
System.out.println（“余额：“+selectedPassenger.getFirstName（）”是：“+selectedPassenger.getBalance（）”）；
//使用促销代码支付经济舱（航班列表）；
打破
}否则{
System.out.println（“不一致的atempts数量：+尝试次数”）；
}
}
}

---

}

您的实际问题是什么？什么东西不能像你希望的那样工作？期望输出和实际输出的区别是什么？将您的代码输入while循环中的促销代码。你需要添加一个中断，这样当有一个好的代码时，你就可以跳出循环。你在开始时只从用户那里获得一次输入。当循环运行时，它会反复使用相同的输入进行检查，而不会给用户重试的机会。

public void chooseClassAndPromoCode(ArrayList<Flight> flightList) {
System.out.println("Pick which class do you want? (1 - economic, 2 - business, 3 - first class)");
int userFlightClass = scanner.nextInt();
scanner.nextLine();

System.out.println("Do you have promo code? (yes / no )");
String yesNoPromoCode = scanner.nextLine();
int attempts = 3;
String userPromoCode = ""
if (yesNoPromoCode.equalsIgnoreCase("yes")) {
    while (attempts-- > 0) {
        System.out.println("Enter promo code");
        userPromoCode = scanner.nextLine();
        if (userPromoCode.equals(selectedFlight.getPromoCode()) && userFlightClass == 1) {
            System.out.println("Price for economic class is: " + selectedFlight.getPriceForEconomicClass());
           // System.out.println("Promo code is valid. You have discount of: 20%, new price is: " + discountEconomyClass());
            System.out.println("Balance of: " + selectedPassenger.getFirstName() + " is: " + selectedPassenger.getBalance());
      //      payingEconomicClassWithPromoCode(flightList);
              break;
        } else {
            System.out.println("Incorrent. Number of atempts: " + attempts);
        }
    }
}