JavaScript Fundamentals

JavaScript Basics

JavaScript · Session 1

Operators & Conditionals

JavaScript · Session 2

Functions

JavaScript · Session 3

Arrays & Loops

JavaScript · Session 4

The DOM — Selecting & Changing Content

JavaScript · Session 5

DOM Styling & classList

JavaScript · Session 6

Events

JavaScript · Session 7

Forms & Validation

JavaScript · Session 8

Mini Project — A To-Do List

JavaScript · Session 9

Putting It All Together

JavaScript · Session 10 · Capstone

Array Methods Deep Dive: map, filter, reduce

You've used push, for and forEach to work with arrays. Now meet the three methods that professional JavaScript code leans on constantly: map (transform), filter (select), and reduce (combine).

Objects & JSON

An array is a numbered LIST of things. An object is a single THING with labeled properties — like a filled-out form instead of a shopping list. And JSON is just objects and arrays written down as text, the format the entire web uses to move data around.

Event Bubbling & Delegation

Ever wonder why clicking a button sometimes seems to trigger its parent's click handler too? That's bubbling — and once you understand it, you can use ONE listener to handle clicks on hundreds of elements, even ones that don't exist yet.

Fetch API: Getting Data from a Server

Everything you've built so far uses data typed directly into your script. Real apps pull data from a server over the network — the fetch() function is how JavaScript asks for it, and how it waits (without freezing) for the answer to come back.

Error Handling with try/catch

Without any error handling, one broken line stops your ENTIRE script cold. try/catch is a safety net: it catches the failure, lets you respond sensibly, and keeps the rest of your page running.