Question

我的程序必须询问电池的数量并显示消息上的数量。为此，我必须传递变量quantity = getQuantity，以便我可以显示所选的电池数量。问题是，当我这样做时，它要求用户输入＆＃34;您想要购买多少电池＆＃34;两次。我正在学习和学生，所以请提供帮助，以提供更好的理解。我不想简单地修改我想要理解的代码。我只是添加数量和其他几个选项，但似乎没有显示所选电池的数量，只询问一次问题。

import javax.swing.JOptionPane;
import java.io.*;


/**
 * @author Arnie 
 */
public class VapeSolutions2 {

    /**
     * @param args
     */
    public static void main(String[] args) {

        // declare variables
        String openingMsg, nameInputMsg, customerName, nameOutputMsg, 
               returnInputMsg, customerReturn, returnOutputMsg, 
               greetingOutputMsg, outputMsg, colorSelection, colorInputMsg,          ColorOutputMsg, priceOutputMsg,
               batteryOutputMsg;
        int quantity;
        double grandTotal;



        // display opening message
        openingMsg = "*** Welcome to Vape Ordering Solutions ***\n"
                   + "                     It's a great day to order a Vape Supplies!";
        JOptionPane.showMessageDialog(null, openingMsg);

        // get required input using dialogs
        nameInputMsg   = "Please enter your name: ";
        customerName   = getStringInput(nameInputMsg);
        returnInputMsg = "Are you a returning customer (yes or no)? ";
        customerReturn = getStringInput(returnInputMsg);
        colorInputMsg  = "What Color would you like?";
        colorSelection = getStringInput(colorInputMsg);
        grandTotal     = totalCost();
        quantity       = getQuantity();


        // build output strings
        nameOutputMsg     = "Welcome " + customerName + ".\n\n";
        returnOutputMsg   = "Your return customer status is " + customerReturn + ".\n";
        greetingOutputMsg = "Thank you for ordering from Vape Ordering Solutions!" + "\n\n"
                          + "Your order will be shipped the following day" + ".\n";  
        ColorOutputMsg    = "Your Color selected is "  + colorSelection + ".\n";
        batteryOutputMsg  = "Total Batteries Ordered is"   + quantity + ".\n";
        priceOutputMsg    = "Your total purchase price is $"  + grandTotal + "\n";













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

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

    private static String getStringInput(String prompt) {
        String input;

        input= JOptionPane.showInputDialog(prompt);
        int i = 0;

        while (input.length() == 0 && i < 3){
            JOptionPane.showInputDialog("Please enter a valid value\n"+ prompt);
            i++;
            if (i == 3){
                JOptionPane.showMessageDialog(null,"You have exceeded the maximum attempts to input correct data");
                System.exit(0);
            }
         }

         return input;
      } 


      private static int getQuantity( ){
          int quantity;
          String quantityMsg = "How many batteries would you like to order?";
          String quant = getStringInput (quantityMsg);
          quantity = Integer.parseInt(quant);
          return quantity;

      }



      // total = grandTotal (quantity, 5,.07)
      private static double totalCost( ) {
          int number; 
          double cost, salesTaxRate, tax, grandTotal, subTotal; 


          cost = (20.00);
          number = getQuantity ();
          salesTaxRate = (.07);
          subTotal = number * cost;
          tax   = subTotal * salesTaxRate;
          grandTotal = subTotal + tax;
          return grandTotal;

      }

} // end class VapeSolutions2

Answer 1

尝试：

quantity       = getQuantity();
grandTotal     = totalCost(quantity);

并更新您的方法＆＃34; totalCost＆＃34;：

// total = grandTotal (quantity, 5,.07)
private static double totalCost( int quantity) {
 //code ...
 number = quantity;
 //code ...
}

如何在没有召回方法的情况下使用变量

1 个答案: