Stage 1 · Lesson 6 of 10
Arrays and objects
hold values in order, and objects hold named properties. Together they model almost all data in JavaScript. Learn the array methods you will use daily: push, pop, includes and indexOf.
Then learn the ones that take a : forEach, map, filter, find and reduce. map and filter return new arrays, while push, sort and splice change the original. sort also compares items as strings by default, so [10, 9, 1].sort() gives [1, 10, 9].
Read object properties with a dot (user.name) or brackets (user["name"]), and loop over them with Object.keys and Object.entries. The built-in and (Map and Set) are better when keys are not simple strings, or when you need unique values. make unpacking and copying short.
A question to check yourself, an AI practice session and 4 cheat sheet entries come when you add the roadmap to your account. Add it
Resources for this stage
Start with· follow one of these
- CoursePaidGrokking JavaScript Fundamentals
Design Gurus · Beginner · $50
The language itself, closures and async included, with runnable exercises per lesson
- GuideFreeJavaScript.info
Ilya Kantor
Free: Part 1 is the most complete modern JavaScript tutorial, with tasks per chapter