JavaScript · Beginner

JavaScript Essentials

Fifty-six browser lessons from console.log to a live course filter: data shapes, DOM building, events, async/await, fetch and the accessibility rules that keep it usable.

56 steps, written for someone starting from zero: the lessons plus a checkpoint quiz task after every ten. Each lesson opens with a starting point you have to change, not the finished answer. Work through it in order and you finish with a program you wrote yourself — the kind of thing you can show in an interview, not a certificate you bought.

56 tasks 6 sections 0 done

Start task 1

Basics

1 Your first value JavaScript —
2 let and const JavaScript —
3 Types JavaScript —
4 Template strings JavaScript —
5 Numbers and Math JavaScript —
6 Comparisons JavaScript —
7 Conditionals JavaScript —
8 Functions JavaScript —
9 Arrays JavaScript —
10 Read the console Concept —

Working with data

11 Objects JavaScript —
12 Arrays of objects JavaScript —
13 filter JavaScript —
14 map again JavaScript —
15 reduce JavaScript —
16 sort JavaScript —
17 Destructuring JavaScript —
18 Spread JavaScript —
19 JSON JavaScript —
20 Shape the data first Concept —

The DOM

21 querySelector JavaScript —
22 textContent JavaScript —
23 classList JavaScript —
24 Creating elements JavaScript —
25 Attributes JavaScript —
26 Events JavaScript —
27 Reading form values JavaScript —
28 Prevent default JavaScript —
29 Rendering a list JavaScript —
30 DOM in order Concept —

Async and APIs

31 Callbacks JavaScript —
32 Promises JavaScript —
33 async / await JavaScript —
34 try / catch with await JavaScript —
35 fetch JavaScript —
36 Check status codes JavaScript —
37 Loading and error states JavaScript —
38 Timeouts JavaScript —
39 Debounce JavaScript —
40 Async is a habit Concept —

Build real features

41 Course card renderer JavaScript —
42 Filter with a search box JavaScript —
43 Sort control JavaScript —
44 Form validation JavaScript —
45 Local storage JavaScript —
46 Countdown timer JavaScript —
47 Simple currency format JavaScript —
48 Accessible toggle JavaScript —
49 Debug like a pro JavaScript —
50 Ship your feature JavaScript —

Capstone: real browser patterns

51 Print a receipt with a template literal JavaScript —
52 Total an array with reduce JavaScript —
53 Shape data with map and destructuring JavaScript —
54 Use a class with a getter JavaScript —
55 Chain promises without a network JavaScript —
56 Recover from bad JSON JavaScript —

Final exam and certificate

Twenty questions from the whole track. Pass mark is 60%. Retakes are free and the best score is the one printed on your certificate.

Create a free account to take the exam