Java To-Do List Application Guide

Creating a To-Do List Application in Java: A Step-by-Step Guide

In this article, we'll walk through the process of creating a simple to-do list application in Java. The application will allow users to add, view, and delete tasks, providing a straightforward example of managing data in a list structure. This project illustrates key concepts such as object-oriented programming and basic data management in Java.

Understanding the Requirements

Before diving into the code, let's outline the requirements for our to-do list application:

• A task should have a title and an optional description.
• Users should be able to add new tasks.
• Users should be able to view all tasks.
• Users should be able to delete tasks.

Designing the Solution

The application will consist of the following components:

1. Task Class: This class will represent a single to-do item with properties for the task's title and description.
2. TaskManager Class: This class will manage a list of tasks and provide methods to add, display, and delete tasks.
3. Main Application: This part of the application will handle user input and interaction, calling the appropriate methods on TaskManager to perform operations.

Implementing the Solution

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

// Task class to represent a task in the to-do list
class Task {
    private String title;
    private String description;

    public Task(String title, String description) {
        this.title = title;
        this.description = description;
    }

    public String getTitle() {
        return title;
    }

    @Override
    public String toString() {
        return "Task: " + title + (description.isEmpty() ? "" : " - " + description);
    }
}

// TaskManager class to manage tasks
class TaskManager {
    private List<Task> tasks;

    public TaskManager() {
        this.tasks = new ArrayList<>();
    }

    public void addTask(String title, String description) {
        tasks.add(new Task(title, description));
    }

    public void viewTasks() {
        if (tasks.isEmpty()) {
            System.out.println("No tasks available.");
        } else {
            for (int i = 0; i < tasks.size(); i++) {
                System.out.println((i + 1) + ". " + tasks.get(i));
            }
        }
    }

    public void deleteTask(int index) {
        if (index < 0 || index >= tasks.size()) {
            throw new IndexOutOfBoundsException("Invalid task index");
        }
        tasks.remove(index);
    }
}

// Main application class
public class TodoListApp {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        TaskManager taskManager = new TaskManager();
        boolean running = true;

        while (running) {
            System.out.println("\nTo-Do List Application");
            System.out.println("1. Add Task");
            System.out.println("2. View Tasks");
            System.out.println("3. Delete Task");
            System.out.println("4. Exit");
            System.out.print("Choose an option: ");

            int choice = scanner.nextInt();
            scanner.nextLine();

            switch (choice) {
                case 1:
                    System.out.print("Enter task title: ");
                    String title = scanner.nextLine();
                    System.out.print("Enter task description (optional): ");
                    String description = scanner.nextLine();
                    taskManager.addTask(title, description);
                    break;
                case 2:
                    taskManager.viewTasks();
                    break;
                case 3:
                    System.out.print("Enter the task number to delete: ");
                    int taskNumber = scanner.nextInt();
                    try {
                        taskManager.deleteTask(taskNumber - 1);
                        System.out.println("Task deleted.");
                    } catch (IndexOutOfBoundsException e) {
                        System.out.println("Invalid task number.");
                    }
                    break;
                case 4:
                    running = false;
                    break;
                default:
                    System.out.println("Invalid option, please try again.");
            }
        }
        scanner.close();
    }
}

Conclusion

This article provided a basic example of how to create a to-do list application in Java. We covered the requirements analysis, design, and implementation of the solution. This program introduces fundamental Java programming concepts and demonstrates the application of object-oriented principles such as encapsulation and abstraction. This type of project serves as a strong starting point for more complex applications.