diff --git a/lib/src/model/coursetable/course.dart b/lib/src/model/coursetable/course.dart
index 1d88c242..848779c0 100644
--- a/lib/src/model/coursetable/course.dart
+++ b/lib/src/model/coursetable/course.dart
@@ -7,20 +7,20 @@ part 'course.g.dart';
 
 @JsonSerializable()
 class Course {
-  late int id;
-  String name;
-  late double stage;
-  late double credit;
-  late int periodCount;
-  String category;
-  late List<String> teachers;
-  late List<String> classNames;
-  late List<CoursePeriod> coursePeriods;
-  late List<String> classrooms;
-  String applyStatus;
-  String language;
-  String syllabusLink;
-  String note;
+  late final int id;
+  final String name;
+  late final double stage;
+  late final double credit;
+  late final int periodCount;
+  final String category;
+  late final List<String> teachers;
+  late final List<String> classNames;
+  late final List<CoursePeriod> coursePeriods;
+  late final List<String> classrooms;
+  final String applyStatus;
+  final String language;
+  final String syllabusLink;
+  final String note;
 
   Course(
       {required this.id,
@@ -55,19 +55,13 @@ class Course {
     required this.note,
   }) {
     id = JsonInit.intInit(idString);
-    name = JsonInit.stringInit(name).trim();
     stage = JsonInit.doubleInit(stageString);
     credit = JsonInit.doubleInit(creditString);
     periodCount = JsonInit.intInit(periodCountString);
-    category = JsonInit.stringInit(category).trim();
     teachers = teacherString.split(RegExp(r"\n")).map((element) => element.trim()).toList();
     coursePeriods = _convertPeriodSlotsToCoursePeriods(periodSlots);
     classrooms = classroomString.split(RegExp(r"\n")).map((element) => element.trim()).toList();
     classNames = classNameString.split(RegExp(r"\n")).map((element) => element.trim()).toList();
-    applyStatus = JsonInit.stringInit(applyStatus).trim();
-    language = JsonInit.stringInit(language).trim();
-    syllabusLink = JsonInit.stringInit(syllabusLink).trim();
-    note = JsonInit.stringInit(note).trim();
   }
 
   bool isEmpty() => id == 0;
diff --git a/lib/src/model/coursetable/course_period.dart b/lib/src/model/coursetable/course_period.dart
index 89dd8d1f..198fd374 100644
--- a/lib/src/model/coursetable/course_period.dart
+++ b/lib/src/model/coursetable/course_period.dart
@@ -4,13 +4,10 @@ part 'course_period.g.dart';
 
 @JsonSerializable()
 class CoursePeriod {
-  int weekday;
-  String period;
+  final int weekday;
+  final String period;
 
-  CoursePeriod({required this.weekday, required this.period}) {
-    weekday = weekday;
-    period = period;
-  }
+  CoursePeriod({required this.weekday, required this.period});
 
   factory CoursePeriod.fromJson(Map<String, dynamic> json) => _$CoursePeriodFromJson(json);
 
diff --git a/lib/src/model/coursetable/course_table.dart b/lib/src/model/coursetable/course_table.dart
index 54168867..797e8df8 100644
--- a/lib/src/model/coursetable/course_table.dart
+++ b/lib/src/model/coursetable/course_table.dart
@@ -7,18 +7,14 @@ part 'course_table.g.dart';
 
 @JsonSerializable()
 class CourseTable {
-  int year;
-  int semester;
-  List<Course> courses;
-  User user;
+  final int year;
+  final int semester;
+  final List<Course> courses;
+  final User user;
   late final Set<int> weekdays = {};
   late final Set<String> periods = {};
 
   CourseTable({required this.year, required this.semester, required this.courses, required this.user}) {
-    year = year;
-    semester = semester;
-    courses = courses;
-    user = user;
     weekdays.addAll(courses
         .map((course) => course.coursePeriods.map((coursePeriod) => coursePeriod.weekday))
         .expand((element) => element));