Level 3
Advanced
Forms, data, and APIs
- Forms
- Data
- Intl
- fetch
- async / await
About this level
The last projects work like small, complete apps. You'll validate a sign-up form with clear errors, drive a quiz entirely from data, handle money so it always adds up exactly, and load data from a real API, including what to do when the network fails. These are skills you'll use on almost every real project.
Before you start
Work through the Intermediate projects first, especially To-do List: the Quiz App and Expense Tracker build on its way of drawing the page from data.
What you'll learn
- Validate forms with built-in and custom checks
- Write error messages everyone can find and understand
- Build an interface from data
- Format money and dates for a country with Intl
- Load data from an API with fetch, async, and await
The projects
- 12
Form Validation
Check a sign-up form before it's sent, first with the browser's own checks, then with clear messages of your own.
17 ideas · 2 ways
- 13
Quiz App
Answer questions one at a time, see straight away if you were right, and get a score at the end.
12 ideas
- 14
Expense Tracker
Track what you spend, with a running total and totals by category that update as you go.
12 ideas
- 15
Random Quote
Fetch a new quote from a public API, with loading and error states, and copy it with one click.
10 ideas