THE JAVASCRIPT PATH

Build understanding.
One concept at a time.

34 lessons across four tiers. Clear explanations, focused examples, and room to test your understanding.

CHAPTER 01

Foundations

Get comfortable with the language itself.

165 MIN OF HANDS-ON LEARNING

What JavaScript is & how it runs

Understand what the language does, what the browser provides, and when code actually runs.

15 min 02

var, let, const & hoisting

Choose declarations deliberately and understand what is available before each line runs.

15 min 03

Block, function & global scope

Keep names where they belong and follow which code can read them.

15 min 04

Data types & value references

Distinguish primitive values from shared objects before you copy or compare them.

15 min 05

Coercion & explicit conversion

Make conversions visible and choose comparisons whose rules you intend.

15 min 06

Operators & short-circuiting

Read arithmetic, comparisons, assignment, and defaults without guessing their order.

15 min 07

Control flow & loops

Choose branches and repeat work with a clear stopping condition.

15 min 08

Functions & reusable behavior

Use declarations, expressions, arrows, parameters, and return values intentionally.

15 min 09

Arrays & objects

Choose collections, access values safely, and notice which operations mutate them.

15 min 10

Basic error handling with try/catch

Catch failures at a useful boundary and keep error information intact.

15 min 11

Strings & numeric operations

Keep text formatting separate from numeric calculations.

15 min

CHAPTER 02

Intermediate

Make the browser respond to your ideas.

180 MIN OF HANDS-ON LEARNING

Lexical scope & the scope chain

Predict name lookup from where a function was defined.

20 min 13

Closures

Give a function private, persistent access to the state it needs.

20 min 14

this, call, apply & bind

Determine this from the call form, with a separate rule for arrows.

20 min 15

Higher-order functions & array methods

Choose a method by the shape of the result you need.

20 min 16

The DOM & node tree

Read the browser’s live document tree and distinguish it from the source text.

20 min 17

Events & event delegation

Handle interaction through the event path and a stable parent.

20 min 18

Timers & their real behavior

Schedule and cancel work without assuming exact timing.

20 min 19

JSON & API-shaped data

Cross the text boundary and validate the shape you received.

20 min 20

Equality & structural comparison

Distinguish identity, value equality, and a domain-specific comparison.

20 min

CHAPTER 03

Advanced

Connect the pieces. Understand what happens underneath.

200 MIN OF HANDS-ON LEARNING

Objects & the prototype chain

Follow property lookup without confusing inheritance with copied fields.

20 min 22

Constructors & classes

Create instances while sharing behavior through prototypes.

20 min 23

The event loop

Trace the call stack, browser work, microtasks, and timer tasks.

20 min 24

Promises & rejection paths

Represent a future result and keep success and failure in the same chain.

20 min 25

async & await

Write promise-based workflows in a readable order without hiding concurrency or failures.

20 min 26

fetch & network errors

Check transport, HTTP status, parsing, and payload shape as separate failure points.

20 min 27

Modules: ESM & CommonJS

Make dependencies explicit and keep file-level state private.

20 min 28

Iterators & generators

Produce one value at a time through the iteration protocol.

20 min 29

Memory & front-end leaks

Trace reachability and release work when a feature is finished.

20 min 30

Debugging as a discipline

Use observations to narrow a failure instead of making untested edits.

20 min

CHAPTER 04

Real-World

Read, debug, measure, and test the code you ship.

80 MIN OF HANDS-ON LEARNING

Reading an unfamiliar codebase

Follow one user action through entry points, data changes, and observable results.

20 min 32

Debugging AI-generated code

Verify generated code with explicit requirements and counterexamples.

20 min 33

Performance: less unnecessary work

Measure first, then reduce repeated computation, rendering, and event work.

20 min 34

A first unit test

Turn a contract into an executable check with a clear expected result.

20 min

Already know where you’re stuck?

Every lesson is open. Jump in, revise, and revisit.

Try a challenge

Build understanding.One concept at a time.

Foundations

What JavaScript is & how it runs

var, let, const & hoisting

Block, function & global scope

Data types & value references

Coercion & explicit conversion

Operators & short-circuiting

Control flow & loops

Functions & reusable behavior

Arrays & objects

Basic error handling with try/catch

Strings & numeric operations

Intermediate

Lexical scope & the scope chain

Closures

this, call, apply & bind

Higher-order functions & array methods

The DOM & node tree

Events & event delegation

Timers & their real behavior

JSON & API-shaped data

Equality & structural comparison

Advanced

Objects & the prototype chain

Constructors & classes

The event loop

Promises & rejection paths

async & await

fetch & network errors

Modules: ESM & CommonJS

Iterators & generators

Memory & front-end leaks

Debugging as a discipline

Real-World

Reading an unfamiliar codebase

Debugging AI-generated code

Performance: less unnecessary work

A first unit test

Already know where you’re stuck?

Build understanding.
One concept at a time.