main.java

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        StudentManagement management = new StudentManagement();
        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("\n1. Add Student");
            System.out.println("2. List Students");
            System.out.println("3. Update Student");
            System.out.println("4. Delete Student");
            System.out.println("5. Exit");
            System.out.print("Choose an option: ");

            int choice = scanner.nextInt();
            scanner.nextLine(); // Consume newline

            switch (choice) {
                case 1:
                    System.out.print("Enter ID: ");
                    int id = scanner.nextInt();
                    scanner.nextLine(); // Consume newline

                    System.out.print("Enter Name: ");
                    String name = scanner.nextLine();

                    System.out.print("Enter Age: ");
                    int age = scanner.nextInt();
                    scanner.nextLine(); // Consume newline

                    System.out.print("Enter Grade: ");
                    String grade = scanner.nextLine();

                    Student student = new Student(id, name, age, grade);
                    management.addStudent(student);
                    System.out.println("Student added successfully!");
                    break;

                case 2:
                    System.out.println("\nList of Students:");
                    for (Student s : management.listStudents()) {
                        System.out.println(s);
                    }
                    break;

                case 3:
                    System.out.print("Enter ID of the student to update: ");
                    int updateId = scanner.nextInt();
                    scanner.nextLine();

                    System.out.print("Enter New Name: ");
                    String newName = scanner.nextLine();

                    System.out.print("Enter New Age: ");
                    int newAge = scanner.nextInt();
                    scanner.nextLine(); 

                    System.out.print("Enter New Grade: ");
                    String newGrade = scanner.nextLine();

                    if (management.updateStudent(updateId, newName, newAge, newGrade)) {
                        System.out.println("Student updated successfully!");
                    } else {
                        System.out.println("Student not found.");
                    }
                    break;

                case 4:
                    System.out.print("Enter ID of the student to delete: ");
                    int deleteId = scanner.nextInt();
                    scanner.nextLine(); 

                    if (management.deleteStudent(deleteId)) {
                        System.out.println("Student deleted successfully!");
                    } else {
                        System.out.println("Student not found.");
                    }
                    break;

                case 5:
                    System.out.println("Exiting program...");
                    scanner.close();
                    return;

                default:
                    System.out.println("Invalid choice. Please try again.");
            }
        }
    }
}