Student Manager

main.dart

import 'dart:io';

/// Beschreibung:
/// Du sollst eine kleine Konsolen-App programmieren, mit
/// der man Studenten anlegen, anzeigen und auswerten kann.
/// Das Programm soll:
/// Einen neuen Studenten aufnehmen (Name, Alter, Note)
/// Alle gespeicherten Studenten anzeigen
/// Die Durchschnittsnote berechnen
/// Beendet werden können

class Student {
  String name;
  int age;
  double? grade;

  // positional required
  Student(this.name, this.age, this.grade);

  @override
  String toString() => '$name (Alter: $age, Note: $grade)';
}

void main() {
  List<Student> students = [];
  while (true) {
    print('1. Student hinzufügen');
    print('2. Alle Studenten anzeigen');
    print('3. Durchschnittsnote berechnen');
    print('4. Beenden');

    int? input = int.tryParse(stdin.readLineSync() ?? "");

    switch (input) {
      case 1:
        createStudent(students);
        break;
      case 2:
        showStudents(students);
        break;
      case 3:
        break;
      case 4:
        return;
      default:
    }
  }
}

void createStudent(List<Student> students) {
  stdout.write("Name: ");
  String? name = stdin.readLineSync();
  stdout.write("Alter: ");
  String? age = stdin.readLineSync();
  int? ageReal = int.tryParse(age ?? "");
  stdout.write("Note: ");
  String? grade = stdin.readLineSync();
  double? gradeReal = double.tryParse(grade ?? "");

  if (name != null &&
      name.trim().isNotEmpty &&
      ageReal != null &&
      gradeReal != null) {
    students.add(Student(name, ageReal, gradeReal));
    print("Student hinzugefügt");
  } else {
    print("Ungültige Eingabe");
  }
}

void showStudents(List students) {
  if (students.isEmpty) {
    print("Keine Studenten");
  } else {
    students.forEach(print);
  }
}

void calcAverage(List<Student> students) {
  double sumOfNotes = 0;

  for (dynamic s in students) {
    sumOfNotes += s.grade!;
  }

  double average = sumOfNotes / students.length;
  print(average);
}