Based on roadmap.sh/javascript
Master let, const, var, hoisting, and block scope — the foundation of JavaScript.
Working with boolean values and truthiness — fundamental to conditional logic.
Numeric operations, special values (NaN, Infinity), and precision — handling numbers correctly.
Arbitrary-precision integers — working with numbers beyond JavaScript's safe integer limit.
Arithmetic, comparison, logical, nullish coalescing, and modern ES2021+ operators.
Understand implicit and explicit type conversion — one of JavaScript's most misunderstood features.
if/else, switch, loops, break/continue, generators — how JavaScript makes decisions.
Function declarations, arrow functions, closures, and higher-order functions — mastering code organization.
Lexical scoping, closures, variable capture — advanced scope concepts.
Object creation, property access, prototype chain — understanding JavaScript's object model.
Prototype chain, inheritance patterns, Object.create — deep dive into object inheritance.
Array methods, iteration, transformation — working with collections of data.
String methods, template literals, pattern matching — text manipulation in JavaScript.
Array and object destructuring — extracting values efficiently from complex data structures.
Opt into safer JavaScript with 'use strict' — prevents silent errors and bad patterns.
Promises, async/await, error handling — managing asynchronous operations.
Async iterators, generators, and patterns — mastering complex asynchronous flows.
Try/catch, error types, custom errors — robust error management.
ES module system: named/default exports, dynamic import, and module patterns.
Creating unique and immutable symbols — advanced identity and privacy patterns.
Generator functions, iterators, and the iterable protocol — advanced iteration patterns.
Pattern matching with regex — powerful text search and validation.
JSON serialization and parsing — working with structured data.
Map and Set collections — better alternatives to objects and arrays for specific use cases.
Weak references for garbage collection — memory-efficient data structures.
Metaprogramming with proxies — intercept and customize operations on objects.
Metaprogramming with Reflect — cleaner way to manipulate objects.
Mathematical functions and constants — performing calculations and random operations.
Working with dates and timezones — managing temporal data.
Working with URLs and query parameters — parsing and manipulating URLs.
Common JavaScript design patterns — proven solutions to recurring problems.
Functional paradigms in JavaScript — pure functions, immutability, composition.
Core algorithms — sorting, searching, and graph traversal.
Low-level binary data handling — working with ArrayBuffer and typed arrays.