Question

班级注册是大学生的一个重要方面。注册课程时，您必须知道课程编号（CRN）。

下表列出了一些CRN及其相应的课程标题。

CRN   | COURSE TITLE   
12451 | Introduction to IT Problem Solving Using Computer Programming  
15349 | Object-Oriented Techniques for IT Problem Solving   
18467 | Applied IT Programming  
16890 | Database Fundamentals  
13334 | Database Programming

我需要创建一个程序来让学生注册这些课程。当用户输入CRN时，会发生一次课程注册。在注册服务商（用户）指示他们已完成输入CRN之前，继续提示用户输入CRN。您必须验证CRN，提供错误消息，并在输入无效CRN时重新提示用户。跟踪每门课程的入学人数。特定CRN的课程注册不能超过其最大注册，否则将显示错误消息，并且不会处理注册。

一旦用户表示他们已完成输入CRN，显示格式正确的报告，其中包含每个课程的列表及其CRN和标题，注册的学生人数以及剩余的座位数。

运行代码后， 1.退出最初几次都没有做任何事情我还没弄明白如何忽略重叠输入 3.我需要将限制设置为30

import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;

class  TwoD
{

        private static boolean typeInt(String a) throws IOException {
  try {
     Integer.parseInt(a);
     return true;
    } catch (NumberFormatException e) {
     return false;
  }
    }

         public static void main(String[] args) throws IOException  
{
     {
         System.out.println("These are the courses that you can choose for the students to enroll. \n 12451 | Introduction to IT Problem Solving Using Computer Programming \n 15349 | Object-Oriented Techniques for IT Problem Solving \n 18467 | Applied IT Programming \n 16890 | Database Fundamentals  \n 13334 | Database Programming");

           ArrayList<String> name = new ArrayList<String>();
                Scanner scan = new Scanner(System.in);

        System.out.print("What is your student's name? ");      
    String student = scan.next();
    String a;

    while(!student.equalsIgnoreCase("quit")) {
        name.add(student); //after a cycle of while, ask user whether he or she would quit and print the arraylist of students.
        System.out.print("What is your student's name? ");
        student = scan.next();

    }

    ArrayList< ArrayList<String> > main = new ArrayList< ArrayList<String> >();
    for(int i = 0; i<name.size(); i++){
       ArrayList<String> course = new ArrayList<String>();
       for (int j = 0; j < name.size(); j++){

            System.out.print("The course the student is currently enrolling is : ");
        a = scan.next();

    while (!a.equalsIgnoreCase("quit"))
    {

  while(!typeInt(a) || Integer.parseInt(a) != 12451 && Integer.parseInt(a) != 15349 && Integer.parseInt(a) != 16890 && Integer.parseInt(a) != 13334 && Integer.parseInt(a) != 18467) {
            System.out.println("Check the courses again.");                     
         a = scan.next();
    }
        course.add(a);

        if (a.equalsIgnoreCase("quit")!=true)
        {
        System.out.print("The course the student is currently enrolling is : ");
        a = scan.next();
        }
        else break;
    }

       }
       main.add(course);
     }

    for(int i = 0; i < name.size(); i++){
        System.out.print("Name " + i + ": ");
        for(int j = 0; j < main.get(i).size(); j++){
            System.out.print(main.get(i).get(j) + " ");
        }
        System.out.println();
    }
}
}
}

Answer 1

这是一个关于如何调试的教程的链接。我过去花了几个小时试图弄清楚我的代码出了什么问题，并在网上寻找答案。最后，我必须知道我的最终项目在截止日期前两小时没有工作。

这项技能将为您提供良好的服务，并在您的职业生涯中为您节省数百小时。

Above mentioned link

需要一些2d arraylists的帮助

1 个答案: