Student.java

import java.util.ArrayList;
import java.util.HashMap;

/**
 * Student class stores student info, enrolled courses, and grades.
 */
public class Student {
    private String name;
    private String id;
    private ArrayList<Course> enrolledCourses;
    private HashMap<Course, Double> grades;

    public Student(String name, String id) {
        this.name = name;
        this.id = id;
        this.enrolledCourses = new ArrayList<>();
        this.grades = new HashMap<>();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public ArrayList<Course> getEnrolledCourses() {
        return enrolledCourses;
    }

    /**
     * Enrolls this student in a course.
     */
    public void enrollInCourse(Course course) {
        if (!enrolledCourses.contains(course)) {
            enrolledCourses.add(course);
            course.enrollStudent();
        }
    }

    /**
     * Assigns a grade to this student for a specific course.
     */
    public void assignGrade(Course course, double grade) {
        if (enrolledCourses.contains(course)) {
            grades.put(course, grade);
        }
    }

    /**
     * Gets the grade for a specific course.
     */
    public Double getGrade(Course course) {
        return grades.get(course);
    }

    /**
     * Gets all grades for this student.
     */
    public HashMap<Course, Double> getAllGrades() {
        return grades;
    }
}