[Applied] Build a Simple To-Do List Tool

In this lesson you'll combine the arrays, objects, functions, loops, and classes you've learned so far to build a simple to-do (task) management tool, deepening your overall understanding as you go. This is for people searching "JavaScript how to build a to-do app" who landed here.

Let's combine arrays, objects, functions, loops, and classes, everything you've learned up to this point, to build a simple to-do (task) management tool. In real app development too, small pieces of functionality like this are combined to build something bigger. This is a capstone lesson where you can really feel how the knowledge from each individual lesson applies to a real app.

The sample code has a TodoList class with a tasks property that manages tasks in an array, along with three methods: add(), complete(), and show(). Each method actually combines operations you've learned before: adding to an array, changing an object's property, and listing everything out with .forEach().

A common beginner stumbling block is getting a grip on the overall picture of code where several pieces of functionality are intertwined. It's easier to understand if you first check the behavior of just add(), then just complete(), one method at a time, before tracing through how they all work together as a whole. Once you're comfortable, try your own extensions too — a delete feature, adding priority levels, and so on.

This example doesn't use a screen (HTML) — it performs "adding a task," "completing it," and "displaying the list" purely through console output. Once you're comfortable, you can also develop it further into a real to-do app by combining it with an HTML <button> (it's worth studying the HTML/CSS lessons alongside this one too).