JavaScript basics

About this track

Variables, logic, functions and the DOM — everything you need before reaching for a framework. Taught here on Yanjye with examples you can run in your browser console.

Every lesson is written and hosted here on Yanjye — you never leave the site. Work through them in order, then sit the exam to earn your certificate.

Create a free account or log in to track your progress and earn the certificate.

Lessons

1. 1
   What JavaScript is and where it runs

   Your first script, and the console you will live in.

   ~15 min
2. 2
   Variables: let, const and var

   Store values and know which keyword to reach for.

   ~25 min
3. 3
   Data types and operators

   The kinds of value JavaScript works with.

   ~25 min
4. 4
   Conditions: if, else and switch

   Make your code decide what to do.

   ~25 min account needed
5. 5
   Loops

   Repeat work without repeating yourself.

   ~25 min account needed
6. 6
   Functions

   Package logic so you can reuse it.

   ~30 min account needed
7. 7
   Arrays and array methods

   Work with ordered lists of values.

   ~30 min account needed
8. 8
   Objects

   Group related values under named keys.

   ~25 min account needed
9. 9
   The DOM: changing the page

   Read and rewrite the page from JavaScript.

   ~30 min account needed
10. 10
    Events

    Respond to clicks, typing and form submissions.

    ~25 min account needed