How JavaScript objects really work under the hood: prototype chains, property descriptors, key enumeration order, and the memory model. Written for working developers who want precise, tested answers instead of folklore.
- Object.getPrototypeOf
Reading and walking the prototype chain — and why
__proto__is not the tool for it. - Own keys: getOwnPropertyNames vs keys vs Reflect.ownKeys
Three similar-looking APIs that answer three different questions. A comparison table with examples.
- Property descriptors
writable, enumerable, configurable — what Object.defineProperty actually controls.
- Memory management in JavaScript
Garbage collection basics, WeakMap and WeakRef, and how to avoid accidental leaks.