Question

这是我正在为样本考试工作的一个问题，但无法弄清楚我在搞乱代码的地方。显然它没有运行。任何提示都会很好。我是java新手。

import java.util.Scanner;

public class TicketProgram {public static void main(String[] args) {

    Scanner in = new Scanner(System.in);

    int totalTickets = 100;
    int ticketsPerPerson = 4;

    do {
        System.out.println("Please enter the total amount of tickets you wish to purchase: (No more than 4) ");
        int ticketsSold = in.nextInt();
        if (ticketsSold > 4){
            System.out.println("Max of 4 ticket.  Please reenter the amount of tickets you want to purchase: ");
        }
        else {
            System.out.println("You have chosen to purchase " + ticketsSold + " tickets.");
            int ticketsLeft = (totalTickets - ticketsSold);
            System.out.println("There are " + ticketsLeft + " left");

        while (ticketsLeft > 0); {
        if (ticketsLeft == 0)
        System.out.println("There are no tickets left. ");} 

    }
}

编译此程序时会出现编译时错误

线程中的异常＆＃34; main＆＃34; java.lang.RuntimeException：无法编译源代码 - 错误的树类型：at TicketProgram.main（TicketProgram.java:19） C：\ Users \用户isaacbrekke \应用程序数据\本地\的NetBeans \缓存\ 8.1 \执行人-片段\ run.xml：53： Java返回：1 BUILD FAILED（总时间：0秒）

Answer 1

这看起来像是一个支架问题。您需要关闭else语句和do循环中的括号。另外，最后两行不应该有围绕它们的括号。

do {
    System.out.println("Please enter the total amount of tickets you wish to purchase: (No more than 4) ");
    int ticketsSold = in.nextInt();
    if (ticketsSold > 4){
        System.out.println("Max of 4 ticket.  Please reenter the amount of tickets you want to purchase: ");
    }
    else {
        System.out.println("You have chosen to purchase " + ticketsSold + " tickets.");
        int ticketsLeft = (totalTickets - ticketsSold);
        System.out.println("There are " + ticketsLeft + " left");
    } 
} while (ticketsLeft > 0); 
    if (ticketsLeft == 0)
    System.out.println("There are no tickets left. ");

Answer 2

试试这个

public class TicketProgram {
   static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        int totalTickets = 100;
        int ticketsPerPerson = 4;
        int ticketsLeft = 0;

        do {
            System.out.println("Please enter the total amount of tickets you wish to purchase: (No more than 4) ");
            int ticketsSold = in.nextInt();
            if (ticketsSold > 4){
                System.out.println("Max of 4 ticket.  Please reenter the amount of tickets you want to purchase: ");
            }
            else {
                System.out.println("You have chosen to purchase " + ticketsSold + " tickets.");
                ticketsLeft = (totalTickets - ticketsSold);
                totalTickets = ticketsLeft;
                System.out.println("There are " + ticketsLeft + " left");
            }}
            while (ticketsLeft > 0); {
            if (ticketsLeft == 0)
            System.out.println("There are no tickets left. ");
            }

        }

        }

Answer 3

在阅读你的作业时，看起来你正在跳过关键部分。作业要求您跟踪100张门票的买家数量。在这里的代码中，我刚刚添加了一个变量来跟踪买家的数量，我只使用一个变量来跟踪你剩下的票数。无需跟踪剩余的总票数和目前购买的总票数。祝你好运！

import java.util.Scanner;

public class TicketSeller {
public static void main(String[] args) {
    int tickets = 100;
    int buyers = 0;
    Scanner in = new Scanner(System.in);

    while(tickets > 0) {
        System.out.println("There are " + tickets + " tickets available.");
        System.out.print("How many would you like to purchase? ");
        int purchase = in.nextInt();
        if (purchase > 0 && purchase <= 4) {
            tickets -= purchase;
            buyers += 1;
        }
        else {
            System.out.println("Sorry, invalid number. Choose between 1 and 4.");
        }
    }

    System.out.println("There were " + buyers + " buyers for the 100 tickets.");
}

}

Answer 4

括号混乱，代码几乎没有我为你修复的逻辑错误。

public static void main(String[] args) {

    Scanner in = new Scanner(System.in);
    int totalTickets = 100;

    while (totalTickets > 0) {
        System.out.println("Please enter the total amount of tickets you wish to purchase: (No more than 4) ");
        int ticketsSold = in.nextInt();
        if (ticketsSold > totalTickets)
        {
            System.out.println("Not enough tickets available. Please reduce and re-enter the amount");
        }
        else if (ticketsSold > 4) {
            System.out.println("Max of 4 ticket.  Please reenter the amount of tickets you want to purchase: ");
        } else {
            System.out.println("You have chosen to purchase " + ticketsSold + " tickets.");
            totalTickets = (totalTickets - ticketsSold);
            System.out.println("There are " + totalTickets + " left");
        }
    }

    if (totalTickets == 0)
        System.out.println("There are no tickets left. ");

    in.close();

}

Answer 5

您有几个问题：

不恰当地使用括号。
ticketsLeft。（在括号后更正）
次要代码格式问题。（在类声明的同一行中使用main(String[] args)丑陋）

如果您还没有使用IDE，我建议您使用IDE（如NetBeans）。你的许多问题已经存在。（根据您的评论，我发现您使用的是NetBeans。然后使用code formatting功能，可能通过执行 Alt + Shift + F < / kbd>，我不记得确切的快捷方式）

这是一个有效的例子：

import java.util.Scanner;

public class TicketProgram {
    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);

        int totalTickets = 100;
        int ticketsPerPerson = 4;
        int ticketsLeft = totalTickets;

        do {
            System.out.println("Please enter the total amount of tickets you wish to purchase: (No more than 4) ");
            int ticketsSold = in.nextInt();
            if (ticketsSold > 4){
                System.out.println("Max of 4 ticket.  Please reenter the amount of tickets you want to purchase: ");
            }
            else {
                System.out.println("You have chosen to purchase " + ticketsSold + " tickets.");
                ticketsLeft = (totalTickets - ticketsSold);
                System.out.println("There are " + ticketsLeft + " left");
            }
        } while (ticketsLeft > 0); 

        if (ticketsLeft == 0) {
            System.out.println("There are no tickets left. ");
        }   
    }
}

Answer 6

此代码将帮助您的程序正常运行，并且您可以改进此程序以获得进一步的逻辑来处理类似的事情，＆＃39;客户试图在仅剩下3个时购买4张票，等等。

import java.util.Scanner;

    public class TicketProgram {

        public static void main(String[] args) {

        Scanner in = new Scanner(System.in);

        int totalTickets = 100;
        int ticketsPerPerson = 4;
        int ticketsLeft = totalTickets;

            do {
                System.out.println("Please enter the total amount of tickets you wish to purchase: (No more than 4) ");
                int ticketsSold = in.nextInt();
                if (ticketsSold > ticketsPerPerson){
                    System.out.println("Max of 4 ticket.  Please reenter the amount of tickets you want to purchase: ");
                }
                else {
                    System.out.println("You have chosen to purchase " + ticketsSold + " tickets.");
                    ticketsLeft = (ticketsLeft - ticketsSold);
                    System.out.println("There are " + ticketsLeft + " left");

                }
                if (ticketsLeft == 0){
                    System.out.println("There are no tickets left. ");
                }


            }while (ticketsLeft > 0);        
        }
    }

Answer 7

使用IDE有助于解决编码时的编译错误。

您的代码中还缺少一个逻辑。如果购买的门票超过剩余的门票，那么你的逻辑就会失败。以下是您的问题的解决方案

import java.util.Scanner;

public class TicketProgram {
         public static void main(String[] args) {

    Scanner in = new Scanner(System.in);

    int totalTickets = 100;
    int ticketsPerPerson = 4;
    int ticketsLeft = totalTickets;

    do {
        System.out.println("Please enter the total amount of tickets you wish to purchase: (No more than 4) ");
        int ticketsSold = in.nextInt();
        if (ticketsSold > 4){
            System.out.println("Max of 4 ticket.  Please reenter the amount of tickets you want to purchase: ");
        }
        else {
            if(ticketsLeft >= ticketsSold){
                System.out.println("You have chosen to purchase " + ticketsSold + " tickets.");
                ticketsLeft = (ticketsLeft - ticketsSold);
                System.out.println("There are " + ticketsLeft + " left");
            }else{

                System.out.println("You have been allocated only " + ticketsLeft + " tickets.");
                ticketsLeft = 0;

            }
        }
    } while (ticketsLeft > 0);

    if (ticketsLeft == 0) {
        System.out.println("There are no tickets left. ");
    }
  }
 }

回顾初学java代码

7 个答案: