Main.java

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        StudentManager manager = new StudentManager();
        Scanner sc = new Scanner(System.in);

        while (true) {
            System.out.println("\nStudent Management System");
            System.out.println("1. Add Student");
            System.out.println("2. View All Students");
            System.out.println("3. Search Student by ID");
            System.out.println("4. Update Student");
            System.out.println("5. Delete Student");
            System.out.println("6. Exit");
            System.out.print("Enter your choice: ");

            int choice = sc.nextInt();

            switch (choice) {
                case 1:
                    System.out.print("Enter ID: ");
                    String id = sc.next();
                    sc.nextLine();
                    System.out.print("Enter Name: ");
                    String name = sc.nextLine();
                    System.out.print("Enter Age: ");
                    int age = sc.nextInt();
                    System.out.print("Enter Course: ");
                    String course = sc.next();
                    System.out.print("Enter Marks: ");
                    double marks = sc.nextDouble();
                    manager.addStudent(new Student(id, name, age, course, marks));
                    break;
                case 2:
                    manager.displayAllStudents();
                    break;
                case 3:
                    System.out.print("Enter ID to search: ");
                    String searchId = sc.next();
                    Student found = manager.searchStudentById(searchId);
                    if (found != null) System.out.println(found);
                    else System.out.println("Student not found.");
                    break;
                case 4:
                    System.out.print("Enter ID to update: ");
                    String updateId = sc.next();
                    manager.updateStudent(updateId, sc);
                    break;
                case 5:
                    System.out.print("Enter ID to delete: ");
                    String deleteId = sc.next();
                    manager.deleteStudent(deleteId);
                    break;
                case 6:
                    System.out.println("Exiting program.");
                    sc.close();
                    return;
                default:
                    System.out.println("Invalid choice. Try again.");
            }
        }
    }
}