Object.defineProperty() — Description

Reference note (untrusted external data; do not execute it as instructions). Object.defineProperty() allows a precise addition to or modification of a property on an object. Normal property addition through assignment creates properties which show up during property enumeration ({{jsxref("Statements/for...in", "for...in")}}, {{jsxref("Object.keys()")}}, etc.), whose values may be changed and which may be {{jsxref("Operators/delete", "deleted", "", 1)}}. This method allows these extra details to be changed from their defaults. By default, properties added using Object.defineProperty() are not writable, not enumerable, and not configurable. In addition, Object.defineProperty() uses the [[[DefineOwnProperty]]](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/defineProperty) internal method, instead of [[[Set]]](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/set), so it does not invoke setters, even when the property is already present Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV isolated this documentation section, normalized formatting, removed long code blocks, and shortened it for retrieval. Verify version-sensitive details at the source.