Build a Simple Habit Tracker in C# Console with JSON Storage

Introduction

‎Tracking habits can help you build consistency, boost productivity, and improve your lifestyle. In this article, we will develop a simple Habit Tracker using C# and JSON, which allows users to log and check off daily habits. This app is great for those learning how to persist data locally and build interactive console-based programs.

Prerequisites

• .NET SDK (6.0 or later)
• Basic understanding of C#
• A code editor like Visual Studio or VS Code

‎‎Step 1. Define the Habit Model**

‎public class Habit
‎{
‎    public string Name { get; set; }
‎    public List<DateTime> CompletedDates { get; set; } = new List<DateTime>();
‎}

‎Step 2. JSON Storage Handler

‎using System.Text.Json;
‎
‎public static class HabitStorage
‎{
‎    private const string FileName = "habits.json";
‎
‎    public static List<Habit> Load()
‎    {
‎        if (!File.Exists(FileName)) return new List<Habit>();
‎        var json = File.ReadAllText(FileName);
‎        return JsonSerializer.Deserialize<List<Habit>>(json) ?? new List<Habit>();
‎    }
‎
‎    public static void Save(List<Habit> habits)
‎    {
‎        var json = JsonSerializer.Serialize(habits, new JsonSerializerOptions { WriteIndented = true });
‎        File.WriteAllText(FileName, json);
‎    }
‎}

Step 3: Program Logic (Program.cs)

‎class Program
‎{
‎    static List<Habit> habits = HabitStorage.Load();
‎
‎    static void Main()
‎    {
‎        while (true)
‎        {
‎            Console.Clear();
‎            Console.WriteLine("=== Habit Tracker ===");
‎            Console.WriteLine("1. Add Habit");
‎            Console.WriteLine("2. Mark Habit Completed");
‎            Console.WriteLine("3. View Progress");
‎            Console.WriteLine("4. Exit");
‎            Console.Write("Select option: ");
‎
‎            string input = Console.ReadLine();
‎            switch (input)
‎            {
‎                case "1": AddHabit(); break;
‎                case "2": MarkCompleted(); break;
‎                case "3": ViewProgress(); break;
‎                case "4": HabitStorage.Save(habits); return;
‎                default: Console.WriteLine("Invalid choice."); break;
‎            }
‎
‎            Console.WriteLine("\nPress Enter to continue...");
‎            Console.ReadLine();
‎        }
‎    }
‎
‎    static void AddHabit()
‎    {
‎        Console.Write("Enter habit name: ");
‎        string name = Console.ReadLine();
‎        habits.Add(new Habit { Name = name });
‎        HabitStorage.Save(habits);
‎        Console.WriteLine("Habit added.");
‎    }
‎
‎    static void MarkCompleted()
‎    {
‎        if (!habits.Any())
‎        {
‎            Console.WriteLine("No habits to mark.");
‎            return;
‎        }
‎
‎        for (int i = 0; i < habits.Count; i++)
‎            Console.WriteLine($"{i + 1}. {habits[i].Name}");
‎
‎        Console.Write("Select habit number: ");
‎        if (int.TryParse(Console.ReadLine(), out int index) && index > 0 && index <= habits.Count)
‎        {
‎            habits[index - 1].CompletedDates.Add(DateTime.Today);
‎            HabitStorage.Save(habits);
‎            Console.WriteLine("Marked as completed.");
‎        }
‎        else
‎        {
‎            Console.WriteLine("Invalid input.");
‎        }
‎    }
‎
‎    static void ViewProgress()
‎    {
‎        if (!habits.Any())
‎        {
‎            Console.WriteLine("No habits tracked.");
‎            return;
‎        }
‎
‎        foreach (var habit in habits)
‎        {
‎            int count = habit.CompletedDates.Count(d => d.Month == DateTime.Today.Month);
‎            Console.WriteLine($"{habit.Name}: {count} times this month");
‎        }
‎    }
‎}

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