Question

我有一个项目，我需要一个方法来工作。我不确定它在哪里弄乱，但我还需要在方法中添加一个循环，只允许3次尝试输入或终止。如果它的空白3次程序应该终止。这需要一个while循环吗？

我很难接受这个。

private static String getStringInput(String prompt) {

    // declare variables
    String openingMsg, nameInputMsg, customerName, nameOutputMsg, 
           returnInputMsg, customerReturn, returnOutputMsg, colorInputMsg, colorSelection, 
           greetingOutputMsg, outputMsg;

    // display opening message
    openingMsg = "*** Welcome to Pizzas-R-Us Online Ordering System ***\n"
               + "                     It's a great day to order a pizza!";
    JOptionPane.showMessageDialog(null, openingMsg);


    // get required input using dialogs
    nameInputMsg   = "Please enter your name: ";
    customerName   = JOptionPane.showInputDialog(nameInputMsg);



    returnInputMsg = "Are you a returning customer (yes or no)? ";
    customerReturn = JOptionPane.showInputDialog(returnInputMsg);

    if (customerReturn.equals("yes"))
    {
        JOptionPane.showMessageDialog(null, "Thanks for coming back!");
    }

    else if (customerReturn.equals("no"))
    {
        JOptionPane.showMessageDialog(null, "Thanks for being New!");
    }

    else
    {
        JOptionPane.showMessageDialog(null, "Invalid Syntax");
    }

    colorInputMsg = "What color would you like (black, silver, gold)";
    colorSelection  = JOptionPane.showInputDialog(colorInputMsg);

    private static double totalCost(int number, double cost, double salesTaxRate)


    // build output strings
    nameOutputMsg     = "Welcome " + customerName + ".\n\n";
    returnOutputMsg   = "Your return customer status is " + customerReturn + ".\n"; 
    colorOutputMsg = "you have selected a " + colorSelection + " watch .\n;
    greetingOutputMsg = "Thank you for visiting Pizzas-R-Us!" + "\n\n"
                      + "Your order should be ready in less than 10 minutes.\n";


    // create and display output string
    outputMsg = nameOutputMsg + returnOutputMsg + colorOutputMsg + greetingOutputMsg;
    JOptionPane.showMessageDialog(null, outputMsg);

    System.exit(0);
} // end main()


public static String getStringInput(String prompt)
{
    String inputValue;

    do
    {
        inputValue - jOptionPane.showInputDialog(prompt);
        if (inputValue == null)
        {
            jOptionPane.showMessageDialog(null, "You have canceled the program");
            System.exit(1);
        }
        if (inputValue.equals(""))
        {
            jOptionPane.showMessageDialog(null, "no input received")
        }

        return inputValue;

    } while(inputValue.equals("" && ));
}

    public static double totalCost(int number, double cost, double salesTaxRate){
}

Answer 1

您的代码可能存在其他问题，我不知道您正在获得什么样的异常，或者它是否会编译，但是这是一种实现循环的方法得到输入3次，如果他们没有输入任何东西，那就很好了：

public static String getStringInput(String prompt) {

    String inputValue;
    int counter = 0;  // introduce counter to track times no input received

    do {
        inputValue = jOptionPane.showInputDialog(prompt);
        if (inputValue == null) {
            jOptionPane.showMessageDialog(null, "You have canceled the program");
            System.exit(1);
        }

        if (inputValue.equals("")) {
            jOptionPane.showMessageDialog(null, "no input received")
            counter++;  // increment the counter
        }
    } while(inputValue.equals("") && counter < 3); // add condition to also exit loop if no input received 3 times

    return inputValue; // moved return outside of loop
}

试图让方法起作用

1 个答案: