Question

我的收银机计划已接近完成，它可以处理销售和退货，并在寄存器中添加或减去这笔钱。

我唯一的问题是，一旦我完成了添加值，例如，程序关闭，我无法弄清楚如何将其循环回选择菜单。我尝试使用do循环和do while循环，但它对我说它输入无效（可能是因为你必须在退出时按F才能停止）。

我怎样才能循环这整个事情？

import java.util.Scanner;
import java.util.ArrayList;


public class Assignment3_000848913
{
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
        ArrayList<Integer> Prices = new ArrayList<Integer>();
        ArrayList<Integer> ReturnPrices = new ArrayList<Integer>();
        int totalRegisterMoney = 0;
        int Choice = 0;

        System.out.print("What would you like to do?");
        System.out.println();
        System.out.print("Press 1. Process a sale");
        System.out.println();
        System.out.print("Press 2. Process a return");
        System.out.println();
        System.out.print("Press 3. Display Money in register");
        System.out.println();
        System.out.print("Press 4. Exit");
        System.out.println();
        Choice = in.nextInt();


        if(Choice == 1)
        {
            //THIS LOOP READS IN ALL THE PRICES//
            System.out.print("Press F when finished.");
            System.out.println();
            do
            {
                System.out.print("Enter the integer price of the item: $");
                int i = in.nextInt();
                Prices.add(i);
                System.out.println();
            }
            while(in.hasNextInt());


            int totalPrice = processSale(Prices);
            totalRegisterMoney = totalRegisterMoney + totalPrice;
            System.out.print("Your total comes to $");
            System.out.println(totalPrice);
        }
        if(Choice == 2)
        {
            System.out.print("Press F when finished.");
            System.out.println();
            do
            {
                System.out.print("Enter the price of the returned item: $");
                int j = in.nextInt();
                ReturnPrices.add(j);
                System.out.println();
            }
            while(in.hasNextInt());


            int returnTotal = processReturn(ReturnPrices);
            if(returnTotal > totalRegisterMoney)
            {
                System.out.print("Sorry, there's not that much money in the register.");
                System.out.println();
            }
            else
            {
                totalRegisterMoney = totalRegisterMoney - returnTotal;
            }

            System.out.print("You've completed the return.");
            System.out.println();
        }
        if(Choice == 3)
        {
            viewBalance(totalRegisterMoney);
        }


    }


    //END OF MAIN

Answer 1

如果你在执行do..while时遇到错误，那么你就可以了。

问题在于写完＆＃39; F＆＃39;要退出选项1，循环返回并尝试转换“F＆＃39; F＆＃39;进入

Choice = in.nextInt();

这导致错误，因为＆＃39; F＆＃39;不是一个数字。你需要放一个

in.next();

之后

while(in.hasNextInt());

这也会发生在您的代码中的选项2

我差不多完了，但是如何循环整个程序呢？

1 个答案: