1. Primitive Types
2. Variables: let, const, var
3. Numbers & Floating Point
4. Strings & Template Literals
5. null vs undefined
6. Truthy & Falsy Values
7. == vs === Equality
8. Implicit Coercion
9. Explicit Type Conversion
10. typeof & instanceof
11. Declarations vs Expressions
12. Arrow Functions
13. Parameters, Defaults & Rest
14. Scope & the Scope Chain
15. Hoisting
16. Closures
17. Closure Patterns
18. The this Keyword
19. call, apply & bind
20. IIFEs & Module Pattern
21. Object Literals & Properties
22. The Prototype Chain
23. Classes
24. this & Static Members
25. Object Utility Methods
26. Array Fundamentals
27. Array Iteration Methods
28. Destructuring & Spread
29. Iterators & Generators
30. Map & Set
31. The Event Loop
32. Callbacks & Timers
33. Promises
34. async / await
35. Promise Combinators
36. ES Modules
37. Error Handling
38. Optional Chaining & Nullish Coalescing
39. Modern ES Features
40. Symbols & Well-Known Symbols