Question

Hello. can anyone solve this. i am having hard time with this. please post a solution ASAP

a) Create a class named Student. Data fields for Student class include an integer Student ID, a String name, and a double CGPA. Methods include a constructor that requires values for all data fields, as well as get and set methods for each of the data fields. b) Create an application that allows a user to enter values for an array of 15 Student objects. Offer the user the choice of displaying the objects in order by either Student ID or CGPA. Save the application as StudentDemo.java. c) Now, create another application that allows you to store an array that acts as a database of any number of Student objects up to 35. While the user decides to continue, offer three options: to add a record to the database, to delete a record from the database, or to change a record in the database. Then proceed as follows:  If the user selects the add option, issue an error message if the database is full. Otherwise, prompt the user for Student ID. If the Student ID already exists in the database, issue an error message. Otherwise, prompt the user for student name, a valid CGPA (>0 and <=4.0) and add the new record to the database.  If the user selects the delete option, issue an error message if the database is empty. Otherwise, prompt the user for Student ID. If the Student ID does not exist, issue an error message. Otherwise, do not access the record for any future processing.  If the user selects the change option, issue an error message if the database is empty. Otherwise, prompt the user for Student ID. If the requested record does 2 not exist, issue an error message. Otherwise, prompt the user for a new CGPA and change the CGPA value for the record.  After each option executes, display the updated database in ascending order by Student ID and prompt the user to select the next action. Save the application as SDatabase.java.  Part c should be done using array but not ArrayList.

Answer 1

thanks for the question, here is the solution to the first part -  b) Create an application that allows a user to enter values for an array of 15 Student objects. Offer the user the choice of displaying the objects in order by either Student ID or CGPA.

Please post the second part of the question as a separate post and I will assist you in that as well. As per Chegg policy, I am instructed to answer the first part only.

Here are the two classes - Student.java and StudentDemo.java

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public class Student{

    private int studentID;
    private String studentName;
    private double CGPA;

    public Student(int studentID, String studentName, double CGPA) {
        this.studentID = studentID;
        this.studentName = studentName;
        this.CGPA = CGPA;
    }

    public int getStudentID() {
        return studentID;
    }

    public void setStudentID(int studentID) {
        this.studentID = studentID;
    }

    public String getStudentName() {
        return studentName;
    }

    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }

    public double getCGPA() {
        return CGPA;
    }

    public void setCGPA(double CGPA) {
        this.CGPA = CGPA;
    }
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

import java.util.Arrays;

import java.util.Comparator;

import java.util.Scanner;



public class StudentDemo {



    public static void main(String[] args) {



        Scanner scanner = new Scanner(System.in);

        Student students[] = new Student[15]; // create an empty array of type Student


                // store the student details in each index of the array
        for (int count = 1; count <= students.length; count++) {

            System.out.print("Enter student ID as an integer: ");

            int id = scanner.nextInt();

            scanner.nextLine();

            System.out.print("Enter student name: ");

            String name = scanner.nextLine();

            System.out.print("Enter student\'s CGPA score: ");

            double cgpa = scanner.nextDouble();



            students[count - 1] = new Student(id, name, cgpa);

        }



        int choice;

        do {

            System.out.println("Enter 1 for displaying by Id 2 for displaying by CGPA score: ");

            choice = scanner.nextInt();

        } while (choice != 1 && choice != 2);



        if (choice == 1) {

            Arrays.sort(students, new Comparator<Student>() {

                @Override

                public int compare(Student studentOne, Student studentTwo) {

                    return -studentTwo.getStudentID() + studentOne.getStudentID();

                }

            });

            System.out.println("Displaying by Student ID in ascending order");

        } else {

            Arrays.sort(students, new Comparator<Student>() {

                @Override

                public int compare(Student studentOne, Student studentTwo) {

                    return Double.compare(studentOne.getCGPA(), studentTwo.getCGPA());

                }

            });

            System.out.println("Displaying by Student CGPA in ascending order");

        }



        for (Student student : students) {

            System.out.println(student.getStudentID() + ", " + student.getStudentName() + ", " + student.getCGPA());

        }

    }

}

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