Question

我已经完成了这个项目，我的java编程类介绍。这是一个信用卡验证程序。我知道我已经非常接近完成了。我需要做的就是询问用户是否要在第一张卡号后输入另一张卡号。通常程序说请输入您的卡号 用户输入卡号 程序确定签证，万事达卡等......然后确定是否有效。很简单。但我需要改变它来说

“请输入卡号”

用户输入卡号

“你想输入另一张卡号吗？”

用户输入是或否

如果是，则该方法重新运行并获得另一个号码，然后继续执行此操作，直到用户拒绝为止。在用户拒绝之后，程序会确定这些卡是签证，万事达卡等......以及它们是否有效。

我的代码发布在下面。我很确定我需要一个while循环，但我不太确定如何设置它。下面的代码只是getcardnumber方法。

TLDR; 在用户停止输入卡号之前，如何重复此操作？

public static String getCardNumber() {
        String cardNumber;
        Scanner keyboard = new Scanner(System.in);
        System.out.println("Please enter the credit card number: ");
        cardNumber = keyboard.nextLine();
        //remove spaces from cardNumber
        cardNumber = cardNumber.replace(" ", "");
        while (!isAllDigits(cardNumber)) {
            System.out.println("The credit card number must contain only the"
                    + " digits 0-9; please re-enter: ");
            cardNumber = keyboard.nextLine();
            //remove spaces from cardNumber
            cardNumber = cardNumber.replace(" ", "");
        }
        //a number containing only digits has been entered
        return cardNumber;
    }

Answer 1

您可以这样做：

public static void main(String[] args){
    boolean b = false;
    do {
        System.out.println("Number 2: ");
        Item2 item2 = new Item2();
        System.out.println("Please enter the credit card number: ");
        Scanner keyboard = new Scanner(System.in);
        System.out.println(checkNumber(keyboard.nextLine(), keyboard));

        System.out.println("Would you like to input another card number? 1=Yes; 2=No");
        int decision = Input.nextInt();

        if (decision == 1){
            b = false;
        }else if (decision == 2){
            b = true;
        }
    }while(b == false);
}

public static String checkNumber(String cardNumber, Scanner keyboard) {
    //remove spaces from cardNumber
    cardNumber = cardNumber.replace(" ", "");
    while (!isAllDigits(cardNumber)) {
        System.out.println("The credit card number must contain only the"
                + " digits 0-9; please re-enter: ");
        cardNumber = keyboard.nextLine();
        //remove spaces from cardNumber
        cardNumber = cardNumber.replace(" ", "");
    }
    //a number containing only digits has been entered
    return cardNumber;
}

使用while循环重复此操作。信用卡验证

1 个答案: