Question

Problem Statement: Registrar’s Office.

This registrar keeps a record of undergraduate students and graduate students.

They want us to write an app that stores their students and displays them to the user.

For each undergrad student, the app will show the name of the student, the student’s id, whether (true/false) the student is going to graduate school and the student’s high school.

For each grad student, the app will show the name of the student, the student’s id, the class that is taught by the student, and whether (true/false) the student is a research assistant.

The user can then select a student and be given the opportunity to take one of two actions:
Action 1: List all of the graduate students that are research assistants

Action 2: Pick a random undergraduate student from the list and set their isGoingToSchool instance variable to true.

The app must redisplay the updated list of students to allow the user to once again choose an action to perform on the list.

Class Student: String name, int id
Class UnderGrad: String highSchool, boolean isGoingToGradSchool

Class Grad: String classTaught, boolean is a research assistant

Special Note: Please complete in Java using BlueJ and make it as simple as possible. Please provide notes for understanding. Thank you.

Answer 1

Program

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;

class Student {//student class
   protected String name;
   protected int id;

   public Student(String name, int id) {
       this.name = name;
       this.id = id;
   }
}

class UnderGrad extends Student {//undergrade class
   private String highSchool;
   private boolean isGoingToSchool;

   public UnderGrad(String name, int id, String highSchool, boolean isGoingToSchool) {
       super(name, id);
       this.highSchool = highSchool;
       this.isGoingToSchool = isGoingToSchool;
   }

   public void setGoingToSchool(boolean isGoingToSchool) {//setting value
       this.isGoingToSchool = isGoingToSchool;
   }

   @Override
   public String toString() {//for showing details of the under grad
       return "Name: " + name + "\nID: " + id + "\nHigh School: " + highSchool + "\n Is Going To School: "
               + isGoingToSchool;
   }
}

class Grad extends Student {//grad class
   private String classTaught;
   private boolean isAResearchAssistant;

   public Grad(String name, int id, String classTaught, boolean isAResearchAssistant) {
       super(name, id);
       this.classTaught = classTaught;
       this.isAResearchAssistant = isAResearchAssistant;
   }

   public boolean isAResearchAssistant() {//getting value
       return isAResearchAssistant;
   }

   @Override
   public String toString() {//showing details of grad
       return "Name: " + name + "\nID: " + id + "\nClass Taught: " + classTaught + "\n Is a Research Assistant: "
               + isAResearchAssistant;
   }
}

public class Test {// driver class for testing
   public static void main(String[] args) throws IOException {
       // for taking console input
       BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

       /* object of Students */
       //add more students accordingly
       ArrayList<UnderGrad> ug = new ArrayList<UnderGrad>();
       ug.add(new UnderGrad("John Wisley", 1, "Something High School", false));
       ug.add(new UnderGrad("Smantha Joe", 2, "Something High School", false));
       ug.add(new UnderGrad("Dave Parker", 3, "Anything High School", false));

       ArrayList<Grad> g = new ArrayList<>();
       g.add(new Grad("Willy Williams", 4, "Science", true));
       g.add(new Grad("Sam Bran", 5, "Maths", false));
       g.add(new Grad("Joe Kent", 6, "English", true));

       System.out.println("*********Registrar Records*********");
       System.out.println();

       while (true) {// infinite loop
           // showing options
           System.out.println("1. Action 1(list research assistant)");
           System.out.println("2. Action 2(change isGoingToSchool to true)");
           System.out.println("3. Exit");
           System.out.println();

           System.out.print("Enter your choice: ");
           int choice = Integer.parseInt(br.readLine());// taking user choice
           switch (choice) {// switch case

           case 1:// for action 1
               System.out.println("List of Graduate Students who are research assistant");
               for (Grad i : g) {
                   if (i.isAResearchAssistant()) {//shwoing research assistant students
                       System.out.println(i);
                       System.out.println();
                   }
               }
               break;

           case 2:// for for action 2
               //getting the random value which will be 1 less than the size of the arraylist
               int ran = (int) (Math.random() * (ug.size()-1));
               ug.get(ran).setGoingToSchool(true);//setting true in the randome value
               System.out.println("List of all Graduate Students after update");
               for (UnderGrad i : ug) {
                   System.out.println(i);
                   System.out.println();
               }
               break;

           case 3:
               System.out.println();
               System.out.println("Thank you for using this app");
               System.exit(0);// exiting the app

           default:
               System.out.println("Wrong Choice! Try Again");
               break;
           }
       }
   }
}

Output

terminated> Test (1) [Java Application] C:\Program Files\Java\jre1.8.0_211\bin\javaw.exe (05-Jul-2019, 12:40:03 pm) Registrar Records********* 1. Action 1(list research assistant) 2. Action 2(change isGoingToSchool to true) 3. Exit Enter your choice: 1 List of Graduate Students who are research assistant Name Willy Williams ID: 4 class Taught: Science Is a Research Assistant: true Name Joe Kent ID 6 class Taught: English Is a Research Assistant: true

1. Action 1(list research assistant) 2. Action 2(change isGoingToSchool to true) 3. Exit Enter your choice: 2 List of all Graduate Students after update Name: John Wisley ID: 1 High School: Something High School Is Going To School: false Name: Smantha Joe ID 2 High School: Something High School Is Going To School: true Name Dave Parker ID: 3 High School: Anything High School Is Going To School: false 1. Action 1(list research assistant) 2. Action 2(change isGoingToSchool to true) 3. Exit Enter your choice: 3 Thank you for using this app

UML

Java Class> Test Java Class>> Student (default package) (default package) Test main(String): void name: String id: int Student(String.int) Java Class>> Java Class>> Grad CUnderGrad (default package) (default package) class Taught: String isAResearchAssistant boolean ahighSchool String isGoingToSchool: boolean Grad(String. int, String, boolean) funderGrad(String,int, String, boolean) isAResearchAssistant)boolean setGoingToSchool(boolean):void toString) String toString).String