leonardomso/33-js-concepts

📜 33 JavaScript concepts every developer should know.

33 Concepts Every JavaScript Developer Should Know Read the Full Guide • Concepts • Translations • Contributing Recognized by GitHub as one of the top open source projects of 2018! --- ## About This repository helps developers master core JavaScript concepts. Each concept includes clear explanations, practical code examples, and curated resources. **[Start learning at 33jsconcepts.com →](https://33jsconcepts.com)** --- ## Concepts ### Fundamentals - **[Primitive Types](https://33jsconcepts.com/concepts/primitive-types)** Learn JavaScript's 7 primitive types: string, number, bigint, boolean, undefined, null, and symbol. Understand immutability, typeof quirks, and autoboxing. - **[Primitives vs Objects](https://33jsconcepts.com/concepts/primitives-objects)** Learn how JavaScript primitives and objects differ in behavior. Understand immutability, call-by-sharing semantics, why mutation works but reassignment doesn't, and how V8 actually stores values. - **[Type Coercion](https://33jsconcepts.com/concepts/type-coercion)** Learn JavaScript type coercion and implicit conversion. Understand how values convert to strings, numbers, and booleans, the 8 falsy values, and how to avoid common coercion bugs. - **[Equality Operators](https://33jsconcepts.com/concepts/equality-operators)** Learn JavaScript equality operators == vs ===, typeof quirks, and Object.is(). Understand type coercion, why NaN !== NaN, and why typeof null returns 'object'. - **[Scope and Closures](https://33jsconcepts.com/concepts/scope-and-closures)** Learn JavaScript scope and closures. Understand the three types of scope, var vs let vs const, lexical scoping, the scope chain, and closure patterns for data privacy. - **[Call Stack](https://33jsconcepts.com/concepts/call-stack