P1_To_Do_List.java

import java.util.ArrayList;
import java.util.Scanner;

public class P1_To_Do_List{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        ArrayList<String> tasks = new ArrayList<>();
        int choice;

        do {
            System.out.println("\n===== To-Do List Application =====");
            System.out.println("1. Add Task");
            System.out.println("2. View Tasks");
            System.out.println("3. Remove Task");
            System.out.println("4. Update Task");
            System.out.println("5. Exit");
            System.out.print("Enter your choice: ");
            choice = scanner.nextInt();
            scanner.nextLine();

            switch (choice) {
                case 1:
                    System.out.print("Enter task: ");
                    String task = scanner.nextLine();
                    tasks.add(task);
                    System.out.println("Task added successfully!");
                    break;

                case 2:
                    System.out.println("\nYour To-Do List:");
                    if (tasks.isEmpty()) {
                        System.out.println("No tasks found!");
                    } else {
                        for (int i = 0; i < tasks.size(); i++) {
                            System.out.println((i + 1) + ". " + tasks.get(i));
                        }
                    }
                    break;

                case 3:
                    System.out.print("Enter task number to remove: ");
                    int removeIndex = scanner.nextInt() - 1;
                    if (removeIndex >= 0 && removeIndex < tasks.size()) {
                        tasks.remove(removeIndex);
                        System.out.println("Task removed successfully!");
                    } else {
                        System.out.println("Invalid task number!");
                    }
                    break;

                case 4:
                    System.out.print("Enter task number to update: ");
                    int updateIndex = scanner.nextInt() - 1;
                    scanner.nextLine(); 
                    if (updateIndex >= 0 && updateIndex < tasks.size()) {
                        System.out.print("Enter new task description: ");
                        tasks.set(updateIndex, scanner.nextLine());
                        System.out.println("Task updated successfully!");
                    } else {
                        System.out.println("Invalid task number!");
                    }
                    break;

                case 5:
                    System.out.println("Exiting... Thank you for using the To-Do List!");
                    break;

                default:
                    System.out.println("Invalid choice! Please try again.");
            }
        } while (choice != 5);

        scanner.close();
    }
}