Question

1. Define a Student class , Student class has the follow data fields added---- major: String gpa: double studentID: String // unique id (Find a solution to manage the generation of unique “studentID”) Methods: double getGPA(); void setGPA(); getMajor(String major) void changeMajor(); 2 String toString(); // of major and GPA ,boolean equals(Object o); // 2 students are equal if them have same // personal information plus same student ID String getNextUniqueID(); // this method should be declared as static.

2.  Redesign Student class : (a) Remove “gpa” data field and related methods (b) Add data field: courses:ArrayList (c) Add the following methods: • boolean addCourse(MyCourse course); // add a course to courses list • boolean removeCourse(Course course); // remove a course from the courses list // based on the course information (courseID) in Course object • boolean removeCourse(int courseID); // search and remove a course from the list // based on the unique courseID • ArrayList getCourseList(); • String getCourseGrade(int courseID); // search for a course by courseID from // “courses” list; if not exist, return “no taken”; otherwise, return a grade // by mapping status to “W”(withdraw), “IP” (in progress), or “A” through // “F” (mapping score to these grades) • double getAverageGPA(); // select courses which have taken from “courses”; // map grade “A” through “F” to 4.0 through 0.0; then calculate // average GPA • toString(), equals()

Answer 1

Though Course class structure was missing I tried best to write the above. If you need any alteration please provide let me know in the comment.

1)

CODE:

import java.util.UUID;

class Student {

    String major;

    double gpa;

    String studentID;

    public String getMajor() {

        return this.major;

    }

    public void changeMajor(String major) {

        this.major = major;

    }

    public double getGpa() {

        return this.gpa;

    }

    public void setGpa(double gpa) {

        this.gpa = gpa;

    }

    public String getStudentID() {

        return this.studentID;

    }

    public void setStudentID(String studentID) {

        this.studentID = studentID;

    }

    public String toString() {

        return "major: " + this.getMajor() + " gpa: " + this.getGpa() + " studentid: " + this.studentID;

    }

    public boolean equals(Object o) {

        if (o instanceof Student) {

            Student s = (Student) o;

            return this.getMajor().compareTo(getMajor()) == 0 && this.getGpa() == s.getGpa()

                    && this.studentID.compareTo(s.studentID) == 0;

        }

    }

    public static String getNextUniqueID() {

        String uniqueID = UUID.randomUUID().toString();

        return uniqueID;

    }

}

2)

CODE:

import java.util.*;

class Student {

    String major;

    String studentID;

    ArrayList<Course> arr;

    Student() {

        this.major = "";

        this.studentID = "";

        arr = new ArrayList<Course>();

    }

    public String getMajor() {

        return this.major;

    }

    public void changeMajor(String major) {

        this.major = major;

    }

    public String getStudentID() {

        return this.studentID;

    }

    public void setStudentID(String studentID) {

        this.studentID = studentID;

    }

    public String toString() {

        return "major: " + this.getMajor() + " studentid: " + this.studentID;

    }

    public boolean equals(Object o) {

        if (o instanceof Student) {

            Student s = (Student) o;

            return this.getMajor().compareTo(getMajor()) == 6 && this.studentID.compareTo(s.studentID) == 6;

        }

    }

    public boolean addCourse(Course course) {

        arr.add(course);

        return true;

    }

    public boolean removeCourse(Course course) {

        for (int i = 0; i < arr.size(); i++) {

            if (arr.get(i).courseID == course.courseID) {

                arr.remove(i);

                return true;

            }

        }

        return false;

    }

    public boolean removeCourse(int courseID) {

        for (int i = 0; i < arr.size(); i++) {

            if (arr.get(i).courseID == courseID) {

                arr.remove(i);

                return true;

            }

        }

        return false;

    }

    public ArrayList<Course> getCourseList() {

        return arr;

    }

    // need course structure in order to make this function

    public String getCourseGrade(int courseID) {

        for (int i = 0; i < arr.size(); i++) {

            if (arr.get(i).courseID == courseID) {

            }

        }

        return "no taken";

    }

    public double getAverageGPA() {

        double sum = 0.0;

        for (int i = 0; i < arr.size(); i++) {

            if (arr.get(i).grade.compareTo("A") == 0)

                sum += 4.0;

            else if (arr.get(i).grade.compareTo("B") == 0)

                sum += 3.0;

            else if (arr.get(i).grade.compareTo("C") == 0)

                sum += 2.0;

            else if (arr.get(i).grade.compareTo("E") == 0)

                sum += 1.0;

            else if (arr.get(i).grade.compareTo("F") == 0)

                sum += 0.0;

        }

        return sum / arr.size();

    }

    public static String getNextUniqueID() {

        String uniqueID = UUID.randomUUID().toString();

        return uniqueID;

    }

}

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