refactoring: Changed to Map instead of list to store both Course and grades

src/main/java/org/example/Student.java

@@ -2,7 +2,9 @@ package org.example;
 
 import java.io.*;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  *  Represents an student user in the system.
@@ -12,7 +14,7 @@ public class Student {
     String studentName;
     String studentId;
     String studentRole;
-    List<Course> courses = new ArrayList<>();
+    Map<Course, String> courseGrades = new HashMap<>();
 
     public Student(){
 
@@ -55,12 +57,12 @@ public class Student {
         this.studentRole = studentRole;
     }
 
-    public List<Course> getCourses() {
-        return courses;
+    public Map<Course, String> getCourseGrades() {
+        return courseGrades;
     }
 
-    public void setCourses(List<Course> courses) {
-        this.courses = courses;
+    public void setCourseGrades(Map<Course, String> courseGrades) {
+        this.courseGrades = courseGrades;
     }
 
     /**