JavaScript
The programming language that makes web pages interactive.
1. Introduction to JavaScript
What JavaScript does, how it runs inside a page, and why these examples write to the page instead of a console.
2. Variables (let, const, var)
Storing values with let and const — and why const should be your default, not let.
3. Data Types
Strings, numbers, booleans, arrays, and objects — the handful of types nearly everything in JavaScript is built from.
4. Operators
Arithmetic, comparison, and logical operators — and why === beats == almost every time.
5. Conditionals (if / else)
Branching logic with if, else if, and else — the exact pattern that decides which path code takes.
6. Loops (for / while)
Repeating code with for loops and while loops — and when to reach for each one.
7. Functions
Packaging reusable logic with function declarations and arrow functions — two syntaxes, the same underlying idea.
8. Arrays
Ordered lists of values, and the methods to work with them — map and filter especially.
9. Objects
Grouping related data as key/value pairs — and the two ways to read a value back out.
10. DOM Manipulation
Reading and changing the page itself with document methods — how JavaScript actually makes a static page interactive.